Transparent electroconductive laminate

ABSTRACT

A transparent electroconductive laminate comprising an organic polymer film having stacked on at least one surface thereof an optical interference layer and a transparent electroconductive layer in this order, the optical interference layer comprising a high refractive-index layer and a low refractive-index layer, with the low refractive-index layer being in contact with the transparent electroconductive layer, and the optical interference layer being composed of a crosslinked polymer, wherein the optical interference layer contains ultrafine particles A comprising a metal oxide and/or a metal fluoride and having a primary diameter of 100 nm or less, and/or at least one of the high refractive-index layer and the low refractive-index layer contains fine particles B having an average primary diameter as large as 1.1 times or more the thickness of the optical interference layer and an average primary diameter of 1.2 μm or less in an amount of 0.5 wt % or less of the crosslinked polymer component. This transparent electroconductive laminate is used as a transparent electrode substrate of a transparent touch panel.

TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to a transparent electroconductivelaminate and a transparent touch panel using the same. Morespecifically, the present invention relates to a transparentelectroconductive laminate comprising an organic polymer film having onone surface thereof an optical interference layer, which is suitable fora touch panel having high reliability in the writing durability, andalso relates to a transparent touch panel using the same.

BACKGROUND ART

[0002] Recently, mobile information terminals equipped with aninformation display and a transparent touch panel for inputtinginformation are overspread. A resistive type transparent touch panelpredominantly used as the transparent touch panel is constituted suchthat two transparent electrode substrates, each having formed thereon atransparent electroconductive layer, are disposed with a spacing ofabout 10 to 100 μm and these two electrodes come into contact only at aportion where an external force is applied and act as a switch toenable, for example, selection of a menu on the display or input ofgraphics and letters.

[0003] The light transmittance of conventional transparent touch panelsis not sufficiently high and, therefore, the display disposed under thetransparent touch panel is hard to see, in many cases. To solve thisproblem, attempts have been made to the usibility of the display byforming an optical interference layer between the organic polymer filmand the transparent electroconductive layer and thereby improving thetransmittance of the transparent electrode substrate. Examples of themethod for forming an optical interference layer include a method offorming a low refractive-index layer and a high refractive-index layerby a vacuum deposition process such as vacuum evaporation andsputtering, and a method of forming layers through hydrolysis andcondensation polymerization of alkoxysilane, titanium alkoxide orzirconium alkoxide and combining the layers to form an opticalinterference layer. A transparent electrode substrate having goodtransmittance may be formed by the former method using a vacuumdeposition process. However, this method has a problem in that writingdurability required of the transparent touch panel can hardly beensured. Furthermore, the vacuum deposition process incurs an increasedproduction cost and therefore, this method is not suitable for massproduction. The latter method is advantageous in view of cost because avacuum deposition process is not used and the processing is performed bycoating. However, in the case of a transparent electrode substrate usinga conventional optical interference layer formed by a coating processand not containing fine particles at all, the layer formed throughhydrolysis and condensation polymerization of titanium alkoxide orzirconium alkoxide in the optical interference layer is readily brokenin a writing durability test and the reliability as a transparentelectroconductive laminate or a transparent touch panel cannot beensured. Even by using these two processes in combination, the writingdurability required of the transparent touch panel can be hardlyensured.

[0004] A first object of the present invention is to provide atransparent electroconductive laminate, and a transparent touch panel,where an optical interference layer can be formed advantageously in viewof cost, excellent transparency is provided and high reliability can beensured in the writing durability and the like required of thetransparent touch panel.

[0005] If the haze of the transparent touch panel increases, the displayquality of the display screen decreases. The quality of the displayscreen may be improved by flattening the transparent electroconductivelayer surface and thereby decreasing the haze, however, it is known thatwhen the transparent electroconductive layer surface of a movableelectrode substrate (a transparent electrode substrate in the inputside) and the transparent electroconductive layer surface of a fixedelectrode substrate (a transparent electrode substrate opposing themovable electrode substrate) both are extremely flat, the transparenttouch panel produced by combining these movable electrode substrate andfixed electrode substrate causes a malfunction. More specifically, whena certain point A on the transparent touch panel is pressed with a penuntil two transparent electroconductive layer surfaces of the movableelectrode substrate and the fixed electrode substrate come into contactand then the pen is moved to another point B, there is sometimes seen aphenomenon that two transparent electroconductive layer surfaces of themovable electrode substrate and the fixed electrode substrate are stillin the state of contacting with each other at the point A, or aphenomenon that separation of two transparent electroconductive layersurfaces of the movable electrode substrate and the fixed electrodesubstrate, which are contacted with each other at the point A, takesmuch time. Such malfunctions of the transparent touch panel are causedby a sticking phenomenon of the transparent electroconductive layersurface of the movable electrode substrate and the transparentelectroconductive layer surface of the fixed electrode substrate witheach other.

[0006] For avoiding malfunctions of the transparent touch panel due tosuch a sticking phenomenon between two transparent electroconductivelayer surfaces of the movable electrode substrate and the fixedelectrode substrate, a method of adding fine particles into a curedresin layer and thereby roughening the transparent electroconductivelayer surface is known (see, for example, Unexamined Japanese PatentPublication (Kokai) No. 8-216327). In this case, the average primarydiameter of the fine particle added in the cured resin layer must belarger than the film thickness of the cured resin layer and therefore,the average primary diameter is usually 2 μm or more. In the case wherea transparent touch panel using a transparent electroconductive laminatehaving a transparent electroconductive layer with the surface thereofbeing roughened by adding, into a cured resin layer, fine particleshaving an average primary diameter larger than the film thickness of thecured resin layer is disposed on a high resolution color liquid crystaldisplay, the display screen glares on viewing the liquid crystal displaythrough the transparent touch panel and the display grade decreases.This occurs because the RGB three primary color lights transmittedthrough the liquid crystal panel are scattered on transmitting throughthe cured resin layer due to the large average primary diameter of thefine particles in the cured resin layer. By reducing the average primarydiameter of the fine particles added in the cured resin layer to besmaller than the film thickness of the cured resin layer, glaring maynot occur but the fine particle added is buried in the cured resin layerto give a substantially flat cured resin layer and the transparent touchpanel malfunctions due to a sticking phenomenon between two transparentelectroconductive layer surfaces of the movable electrode substrate andthe fixed electrode substrate. As such, the method of adding fineparticles in a cured resin layer constituting the transparentelectroconductive laminate and thereby roughening the transparentelectroconductive layer surface has a problem that, when observedthrough the transparent touch panel, the display of the high resolutioncolor liquid crystal display is deteriorated.

[0007] A second object of the present invention is to provide atransparent electroconductive laminate ensuring excellent display gradeof a liquid crystal display on observing the liquid crystal displaythrough a transparent touch panel in the state that the transparenttouch panel is disposed on a high resolution color liquid crystaldisplay.

DISCLOSURE OF THE INVENTION

[0008] (1) A transparent electroconductive laminate comprising anorganic polymer film having stacked thereon a transparentelectroconductive layer, wherein:

[0009] an optical interference layer and a transparent electroconductivelayer are sequentially stacked on at least one surface of the organicpolymer film,

[0010] the optical interference layer comprises a high refractive-indexlayer and a low refractive-index layer, with the low refractive-indexlayer being in contact with the transparent electroconductive layer, and

[0011] the high refractive-index layer and the low refractive-indexlayer are each composed of a crosslinked polymer, at least one of thehigh refractive-index layer and the low refractive-index layercontaining a metal oxide and/or metal fluoride ultrafine particle havinga primary particle size of 100 nm or less.

[0012] (2) The transparent electroconductive laminate as described in(1) above, wherein the metal oxide and/or metal fluoride is at least onemember selected from the group consisting of Al₂O₃, Bi₂O₃, CeO₂, In₂O₃,In₂O₃.SnO₂, HfO₂, La₂O₃, MgF₂, Sb₂O₅, Sb₂O₅.SnO₂, SiO₂, SnO₂, TiO₂,Y₂O₃, ZnO and ZrO₂.

[0013] (3) The transparent electroconductive laminate as described in(1) and (2) above, wherein the crosslinked polymer of at least one ofthe high refractive-index layer and the low refractive-index layer isone formed by hydrolysis and condensation polymerization of a metalalkoxide.

[0014] (4) The transparent electroconductive laminate as described in(3) above, wherein the weight ratio of the ultrafine particle to themetal alkoxide is from 5:95 to 80:20.

[0015] (5) The transparent electroconductive laminate as described in(4) above, wherein the high refractive-index layer is one formed byhydrolysis and condensation polymerization of a mixture comprising theultrafine particle and alkoxysilane at a weight ratio of 5:95 to 80:20.

[0016] (6) The transparent electroconductive laminate as described in(3) above, wherein the high refractive-index layer is one formed byhydrolysis and condensation polymerization of a mixture comprising theultrafine particle and a metal alkoxide at a weight ratio of 1:99 to60:40 and the metal alkoxide is mainly comprised of a metal alkoxideother than alkoxysilane.

[0017] (7) The transparent electroconductive laminate as described in(1) above, wherein the high refractive-index layer is composed of amixture comprising the ultrafine particle and the heat-curable resin orradiation-curable resin at a polymerization ratio of 5:95 to 80:20.

[0018] (8) The transparent electroconductive laminate as described in(1) and (2) above, wherein the crosslinked polymer of at least one ofthe high refractive-index layer and the low refractive-index layer is aheat-curable resin or a radiation-curable resin.

[0019] (9) The transparent electroconductive laminate as described in(1) to (8) above, wherein the difference in the refractive index betweenthe high refractive-index layer and the low refractive-index layer is0.2 or more.

[0020] (10) The transparent electroconductive laminate as described in(1) to (9) above, wherein at least one of the high refractive-indexlayer and the low refractive-index layer contains a second fine particlehaving an average primary particle size as large as 1.1 times or morethe film thickness of the optical interference layer and an averageprimary particle size of 1.2 μm or less, and the content of the secondfine particle is 0.5 wt % or less of the crosslinked polymer componentconstituting the high refractive-index layer and/or low refractive-indexlayer containing the second fine particle.

[0021] (11) The transparent electroconductive laminate as described in(1) to (10) above, which comprises a cured resin layer between theorganic polymer film and the optical interference layer.

[0022] (12) The transparent electroconductive laminate as described in(1) to (11) above, wherein the cured resin layer is composed of aheat-curable or radiation-curable resin and has a film thickness of 2 to5 μm.

[0023] (13) The transparent electroconductive laminate as described in(11) and (12) above, wherein the cured resin layer contains a third fineparticle.

[0024] (14) The transparent electroconductive laminate as described in(1) above, wherein the high refractive-index layer is one formed byhydrolysis and condensation polymerization of a mixture comprising theultrafine particle and a metal alkoxide, the metal alkoxide is mainlycomprised of a metal alkoxide other than alkoxysilane, the lowrefractive-index layer is one formed by hydrolysis and condensationpolymerization of alkoxysilane, the ultrafine particle is TiO₂, and thethird fine particle is a silica particle.

[0025] (15) The transparent electroconductive laminate as described in(1) to (14) above, wherein a transparent substrate is stacked on thesurface of the organic polymer film opposite the optical interferencelayer, through a transparent elastic layer having a Young's modulussmaller than that of the organic polymer film.

[0026] (16) A transparent electroconductive laminate comprising anorganic polymer film having stacked thereon a transparentelectroconductive layer, wherein

[0027] an optical interference layer and a transparent electroconductivelayer are sequentially stacked on at least one surface of the organicpolymer film,

[0028] the optical interference layer comprises a high refractive-indexlayer and a low refractive-index layer, with the low refractive-indexlayer being in contact with the transparent electroconductive layer,

[0029] the optical interference layer is composed of a crosslinkedpolymer,

[0030] at least one of the high refractive-index layer and the lowrefractive-index layer contains a fine particle B having an averageprimary particle size as large as 1.1 times or more the film thicknessof the optical interference layer and an average primary particle sizeof 1.2 μm or less, and

[0031] the content of the fine particle B is 0.5 wt % or less of thecrosslinked polymer constituting the high refractive-index layer and/orlow refractive-index layer containing the fine particle B.

[0032] (17) The transparent electroconductive laminate as described in(16) above, wherein the crosslinked polymer is a polymer formed byhydrolysis and condensation polymerization of a metal alkoxide or is aheat-curable or radiation-curable resin.

[0033] (18) The transparent electroconductive laminate as described in(16) and (17) above, wherein at least one of the high refractive indexand the low refractive-index layer contains an ultrafine particle Ahaving an average primary particle size of 100 μm or less at a weightratio (ultrafine particle A): (crosslinked polymer) of 0:100 to 80:20.

[0034] (19) The transparent electroconductive laminate as described in(18) above, wherein the high refractive-index layer is composed of amixture comprising the ultrafine particle A and the heat-curable orradiation-curable resin at a polymerization ratio of 5:95 to 80:20.

[0035] (20) The transparent electroconductive laminate as described in(16) to (19) above, which comprises a cured resin layer between theorganic polymer film and the optical interference layer.

[0036] (21) The transparent electroconductive laminate as described in(20) above, wherein the cured resin layer is composed of a heat-curableor radiation-curable resin and has a film thickness of 2 to 5 μm.

[0037] (22) The transparent electroconductive laminate as described in(20) and (21) above, wherein the cured resin layer does not contain afine particle larger than the thickness of the cured resin layer.

[0038] (23) The transparent electroconductive laminate as described in(16) above, wherein the high refractive-index layer is one formed byhydrolysis and condensation polymerization of a mixture comprising thefine particle B and a metal alkoxide, the metal alkoxide is mainlycomprised of a metal alkoxide other than alkoxysilane, the lowrefractive-index layer is one formed by hydrolysis and condensationpolymerization of alkoxysilane, and the fine particle B is silica.

[0039] (24) The transparent electroconductive laminate as described in(16) to (23) above, wherein a transparent substrate is stacked on thesurface of the organic film layer opposite the optical interferencelayer, through a transparent elastic layer having a Young's modulussmaller than that of the organic polymer film.

[0040] (25) A transparent touch panel comprising two transparentelectrode substrates each having on at least one surface thereof atransparent electroconductive layer, the two transparent electrodesubstrates being disposed such that the transparent electroconductivelayers face each other, wherein at least one transparent electrodesubstrate is the transparent electroconductive laminate described in (1)to (24) above.

[0041] (26) The transparent touch panel as described in (25) above,wherein a movable electrode substrate and a fixed electrode substrateare both a transparent electroconductive laminate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0042]FIGS. 1A and 1B each is a view showing a constitution example ofthe transparent electroconductive laminate of the present invention.

[0043]FIG. 2 is a view showing another constitution example of thetransparent electroconductive laminate of the present invention.

[0044]FIG. 3 is a schematic view of a touch panel.

[0045]FIG. 4 is a view showing a constitution example where a touchpanel is fixed on a liquid crystal display device.

[0046]FIGS. 5 and 6 each is a view schematically showing the touch panelof Example.

MODE FOR CARRYING OUT THE INVENTION

[0047] The transparent electroconductive laminate of the presentinvention is obtained by stacking an optical interference layer and atransparent electroconductive layer in this order on at least onesurface of an organic polymer film.

[0048]FIGS. 1A and 1B each shows a constitution example of thetransparent electroconductive laminate of the present invention. InFIGS. 1A and 1B, a cured resin layer 2 (only in FIG. 1B), a highrefractive-index layer 3, a low refractive-index layer 4 (these high andlow refractive-index layers work out to an optical interference layer)and a transparent electroconductive layer 5 are formed in this order onone surface of an organic polymer film 1, and a cured resin layer 6 isformed on another surface of the organic polymer film 1.

[0049] In the transparent electroconductive laminate of the presentinvention, the cured resin layer 2 is not essential (FIG. 1A) but ispreferably formed (FIG. 1B).

[0050] The transparent electroconductive laminate of the presentinvention is characterized by adding a specific fine particle having aspecific diameter preferably in a specific amount to the opticalinterference layer for the purpose of adjusting the refractive index orroughening the surface.

[0051] (1) Optical Interference Layer

[0052] The optical interference layer of the present invention comprisesa high refractive-index layer and a low refractive-index layer and thelow refractive layer is in contact with the transparentelectroconductive layer. The high refractive-index layer and the lowrefractive-index layer each is composed of a crosslinked polymer and atleast one of these layers contains a fine particle as described above.

[0053] As the crosslinked polymer for use in the present invention, acrosslinked polymer obtained by the hydrolysis and condensationpolymerization of a metal alkoxide, or a crosslinked polymer of athermosetting resin or a radiation-curable resin can be used.

[0054] (1a) Crosslinked Polymer Obtained by Hydrolysis and CondensationPolymerization of Metal Alkoxide

[0055] Among the crosslinked polymers obtained by the hydrolysis andcondensation polymerization of a metal alkoxide, crosslinked polymersobtained by the hydrolysis and condensation polymerization of titaniumalkoxide, zirconium alkoxide or alkoxysilane are preferred because thesepolymers ensure excellent properties in, for example, mechanicalstrength, stability, and adhesion to a transparent electroconductivelayer, a substrate or the like.

[0056] Examples of the titanium alkoxide include titaniumtetraisopropoxide, tetra-n-propyl orthotitanate, titaniumtetra-n-butoxide and tetrakis(2-ethylhexyloxy) titanate. Examples of thezirconium alkoxide include zirconium tetraisopropoxide and zirconiumtetra-n-butoxide.

[0057] Examples of the alkoxysilane include tetramethoxysilane,tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane,dimethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, vinyltrimethoxysilane,N-β(aminoethyl)_(y)-aminopropyltrimethoxysilane,N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane andγ-aminopropyltriethoxysilane. In many cases, these silicon alkoxides arepreferably used by mixing two or more thereof as needed in view ofmechanical strength or adhesion of the layer, solvent resistance and thelike. Particularly, a silicon alkoxide having an amino group within themolecule is preferably contained at a weight ratio of 0.5 to 60%, morepreferably from 0.5 to 40%, in the entire silicon alkoxide composition.

[0058] The metal alkoxide may be used as a monomer or after previouslyforming it into an appropriate oligomer by the hydrolysis andcondensation polymerization but, usually, a coating solution resultingfrom dissolution and dilution in an appropriate organic solvent iscoated on a lower layer. In the coating film formed on the lower layer,hydrolysis proceeds due to moisture in the air and subsequentlydehydration condensation polymerization proceeds. An appropriate heatingtreatment is generally necessary for accelerating the condensationpolymerization and in a process of the coating method, a heat treatmentat a temperature of 100° C. or more is preferably applied for a fewminutes or more. Depending on the case, active rays such as ultravioletlight may be irradiated on the coating film simultaneously with theabove-described heat treatment so as to increase the crosslinkingdegree.

[0059] The diluting solvent is suitably an alcohol-base orhydrocarbon-base solvent such as ethanol, 2-propanol, butanol,2-methyl-1-propanol, 1-methoxy-2-propanol, hexane, cyclohexane andligroin. Other than these, a polar solvent such as xylene, toluene,cyclohexanone, methyl isobutyl ketone and isobutyl acetate can be alsoused. These solvents can be used individually or as a mixed solvent oftwo or more thereof.

[0060] (1b) Radiation-Curable Resin and Thermosetting Resin

[0061] Examples of the crosslinked polymer for use in the presentinvention include a polyfunctional polyacrylate-base radiation-curableresin starting from polyol acrylate, polyester acrylate, urethaneacrylate, epoxy acrylate or the like, and a thermosetting resin such asmelamine-base thermosetting resin starting from etherifiedmethylolmelamine or the like, phenoxy-base thermosetting resin andepoxy-base thermosetting resin. Among these, a polyfunctionalpolyacrylate-base radiation-curable resin is preferred.

[0062] The radiation-curable resin means a resin where polymerizationproceeds by the irradiation of a radiation such as ultraviolet light oran electron beam. Examples thereof include an acryl-base resincontaining, in the resin composition, a polyfunctional acrylatecomponent having two or more acryloyl groups within the unit structure.

[0063] Specific examples of the starting material of giving thisacryl-base resin, which is preferably used, include various acrylatemonomers such as trimethylolpropane triacrylate, trimethylolpropaneethylene oxide-modified triacrylate, trimethylolpropane propyleneoxide-modified triacrylate, isocyanuric acid ethylene oxide-modifiedtriacrylate, pentaerythritol tetraacrylate, dipentaerythritolpentaacrylate, dipentaerythritol hexaacrylate anddimethyloltricyclodecane diacrylate, and polyfunctional acrylateoligomers of polyester-modified acrylate, urethane-modified acrylate orepoxy-modified acrylate. These resins may be used as a singlecomposition or a mixed composition of several kinds. Depending on thecase, it is also preferred to add an appropriate amount of a hydrolysiscondensate of various silicon alkoxides to the composition.

[0064] In the case of performing the polymerization of the resin layerby the irradiation with ultraviolet light, a known photoinitiator isadded in an appropriate amount. Examples of the photoreaction initiatorinclude acetophenone-base compounds such as diethoxyacetophenone,2-methyl-1-{4-(methylthio)phenyl}-2-morpholinopropane,2-hydroxy-2-methyl-1-phenylpropan-1-one and 1-hyroxycyclohexyl phenylketone; benzoin-base compounds such as benzoin and benzyldimethyl ketal;benzophenone-base compounds such as benzophenone and benzoylbenzoicacid; and thioxanthone-base compounds such as thioxanthone and2,4-dichlorothioxanthone.

[0065] Examples of the phenoxy-base thermosetting resin include a resinobtained by thermally crosslinking a phenoxy resin, a phenoxy etherresin or a phenoxy ester resin represented by the following formula (1),with a polyfunctional isocyanate compound.

[0066] wherein R¹ to R⁶ may be the same or different and each representshydrogen or an alkyl group having from 1 to 3 carbons, R⁷ represents analkylene group having from 2 to 5 carbons, X represents an ether groupor an ester group, m represents an integer of 0 to 3, and n representsan integer of 20 to 300. Among these resins, those where R¹ and R² are amethyl group, R³ to R⁶ are hydrogen and R⁷ is a pentylene group arepreferred in view of productivity because the synthesis is easy.

[0067] The polyfunctional isocyanate compound is sufficient if it is acompound having two or more isocyanate groups within one molecule, andexamples thereof include polyisocyanates such as 2,6-tolylenediisocyanate, 2,4-tolylene diisocyanate, tolylenediisocyanate-trimethylol propane adduct,tert-cyclohexane-1,4-diisocyanate, m-phenylene diisocyanate, p-phenylenediisocyanate, hexamethylene diisocyanate, 1,3,6-hexamethylenetriisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate,tolidine diisocyanate, xylylene diisocyanate, hydrogenated xylylenediisocyanate, diphenylmethane-4,4′-diisocyanate, hydrogenateddiphenylmethane-4,4′-diisocyanate, lysine diisocyanate, lysine estertriisocyanate, triphenylmethane triisocyanate,tris(isocyanatophenyl)thiophosphate, m-tetramethylxylylene diisocyanate,p-tetramethylxylylene diisocyanate, 1,6,11-undecane triisocyanate,1,8-diisocyanate-4-isocyanate methyloctane, bicycloheptanetriisocyanate, 2,2,4-trimethylhexamethylene diisocyanate and2,4,4-trimethylhexamethylene diisocyanate, and a mixture or a polyhydricalcohol adduct thereof. Among these, 2,6-tolylene diisocyanate,2,4-tolylene diisocyanate, tolylene diisocyanate-trimethylol propaneadduct and hexamethylene diisocyanate are preferred in view ofgeneral-purpose use and reactivity.

[0068] In addition, a known tertiary amine such as triethylene diamine,or an organic tin compound such as dibutyltin dilaurate, may be added asa reaction accelerator to improve the crosslinking rate.

[0069] As the epoxy-base thermosetting resin, various types can be usedbut among those, a resin obtained by thermally crosslinking a novolakepoxy resin represented by the following formula (2), is preferred.

[0070] wherein R⁸ represents hydrogen or a methyl group, R⁹ representshydrogen or a glycidyl phenyl ether group, and q represents an integerof 1 to 50. In practice, the value of q generally has a distribution andis difficult to specify but as the average number, the value ispreferably larger and q is preferably 3 or more, more preferably 5 ormore.

[0071] For crosslinking the epoxy resin, a known curing agent is used.Examples of the curing agent include amine-base polyaminoamide types,acids, acid anhydrides, imidazoles, mercaptanes and phenolic resins.Among these, acid anhydrides and alicyclic amines are preferred, andacid anhydrides are more preferred. Examples of the acid anhydrideinclude alicyclic acid anhydrides such as methylhexahydrophthalicanhydride and methyltetrahydrophthalic anhydride, aromatic acidanhydrides such as phthalic anhydride, and aliphatic acid anhydridessuch as dodecenylphthalic anhydride. Among these,methylhexahydrophthalic anhydride is preferred. Examples of thealicyclic amine include bis(4-amino-3-methyldicyclohexyl)methane,diaminocyclohexylmethane and isophoronediamine. Among these,bis(4-amino-3-methyldicyclohexyl)methane is preferred.

[0072] In the case of using an acid anhydride as the curing agent, areaction accelerator for accelerating the curing reaction between theepoxy resin and the acid anhydride may be added. Examples of thereaction accelerator include curing catalysts such as known secondary ortertiary amines (e.g., benzylmethylamine,2,4,6-tris(dimethylaminomethyl)phenol, pyridine,1,8-diazabicyclo(5,4,0)undecene-1) and imidazoles.

[0073] In practical coating of the crosslinked polymer, theabove-described compound and various additives (e.g., curing agent,catalyst) are dissolved in an organic solvent of various types and afteradjusting the concentration or viscosity, the obtained coating solutionis coated on a lower layer. Thereafter, the layer is cured byirradiating a radiation or applying a heat treatment. Examples of thecoating method include various coating methods such as microgravurecoating method, Mayer bar coating method, direct gravure coating method,reverse roll coating method, curtain coating method, spray coatingmethod, comma coating method, die coating method, knife coating methodand spin coating method.

[0074] (1c) Ultrafine Particle A (for Adjusting Refractive Index)

[0075] In general, the layer formed by the hydrolysis and condensationpolymerization of a metal alkoxide, and the crosslinked polymer of athermosetting resin or a radiation-curable resin are known to exhibitgood adhesion to various coating layers. However, if the opticalinterference layer is formed by stacking only the crosslinked polymerlayers, the optical interference layer does not function due to thesmall difference in the refractive index and a transparentelectroconductive laminate having high transmittance cannot be formed,though the adhesion to each layer of the cured resin layer and thetransparent electroconductive layer is preferably improved and therebythe writing durability may be improved.

[0076] To solve this problem, in the present invention, a specifictransparent fine particle having a specific diameter (hereinaftersometimes referred to as a fine particle A) is incorporated into thecrosslinked polymer layer preferably in a specific amount so as togenerate a difference in the refractive index between respective layersconstituting the optical interference layer. By incorporating a specifictransparent fine particle into the optical interference layer composedof a crosslinked polymer, the adhesion between respective layers and thewriting durability can be improved while imparting a desired refractiveindex to the optical interference layer. If the fine particle is merelyadded, there may arise a problem that the formed layer becomes white. Inthe present invention, a metal oxide and/or metal fluoride fine particleis used for generating a difference in the refractive index betweenrespective layers constituting the optical interference layer whileensuring good adhesion of the optical interference layer, and thediameter of the fine particle and preferably further the blending ratioare controlled, whereby a good optical interference layer can be formedwithout causing whitening of the film. By this formation of the opticalinterference layer, the present invention has been accomplished.

[0077] The refractive index of the optical interference layer can beadjusted as such by adding an ultrafine particle without causingwhitening of the film and, as a result, excellent adhesion to theadjacent layer and a large difference in the refractive index can berealized in the combination of a high refractive-index layer and a lowrefractive-index layer and thereby, a transparent electroconductivelaminate having excellent writing durability and a high transmittancecan be formed.

[0078] A first aspect of the present invention has been accomplishedbased on this finding.

[0079] In the optical interference layer according to the first aspectof the present invention, the refractive index of each layerconstituting the optical interference layer is adjusted by adding aspecific ultrafine particle to at least one of a high refractive-indexlayer and a low refractive-index layer, especially to a highrefractive-index layer, each composed of the above-described crosslinkedpolymer.

[0080] The ultrafine particles for use in the present invention musthave a primary diameter of 100 nm or less. By controlling the primarydiameter of the ultrafine particles to 100 nm or less, a good opticalinterference layer can be formed without causing whitening of the film.The primary diameter is preferably 80 nm or less, more preferably 60 nmor less. The lower limit is 5 nm, though this is not particularlylimited.

[0081] This ultrafine particle mainly comprises a metal oxide and/or ametal fluoride. Examples of the metal oxide and metal fluoride includeAl₂O₃, Bi₂O₃, CeO₂, In₂O₃, In₂O₃.SnO₂, HfO₂, La₂O₃, MgF₂, Sb₂O₅,Sb₂O₅.SnO₂, SiO₂′ SnO₂, TiO₂, Y₂O₃, ZnO and ZrO₂.

[0082] Among these, Bi₂O₃, CeO₂, In₂O₃, In₂O₃.SnO₂, HfO₂, La₂O₃, Sb₂O₅,Sb₂O₅.SnO₂, SnO₂, TiO₂, Y₂O₃, ZnO and ZrO₂ are preferred as theultrafine particles contained in the high refractive-index layer, andAl₂O₃, MgF₂ and SiO₂ are preferred as the ultrafine particles containedin the low refractive-index layer.

[0083] These ultrafine particles may be used individually or incombination of two or more thereof.

[0084] The weight ratio of the ultrafine particles and the crosslinkedpolymer is preferably from 1:99 to 80:20, more preferably from 5:95 to80:20. If the weight ratio of the ultrafine particles and thecrosslinked polymer is less than 1:99, the effect of adjusting therefractive index cannot be obtained, whereas if the weight ratio of theultrafine particles and the crosslinked polymer exceeds 80:20, thestrength and adhesive property necessary for the optical interferencelayer may be insufficient. The weight ratio is still more preferablyfrom 30:70 to 65:35. In practice, the weight ratio of the ultrafineparticles and the crosslinked polymer is preferably determined based onthe use ratio at the time of preparing the coating solution of theultrafine particles and the starting material constituting thecrosslinked polymer.

[0085] The ultrafine particle may be incorporated into the crosslinkedpolymer by mixing the ultrafine particle in the starting material of thecrosslinked polymer at the initial stage in the above-described processof producing a crosslinked polymer layer, then coating it as describedabove and performing hydrolysis and condensation polymerization orperforming a crosslinking reaction.

[0086] (1d) High Refractive-index Layer and Low Refractive-index Layer

[0087] The optical interference layer comprises at least one highrefractive-index layer and at least one low refractive-index layer andmay comprise two or more combination units of a high refractive-indexlayer and a low refractive-index layer. In the case where the opticalinterference layer consists of one high refractive-index layer and onelow refractive-index layer, the thickness of the optical interferencelayer is preferably from 30 to 150 nm, more preferably from 50 to 150nm.

[0088] The high refractive-index layer constituting the opticalinterference layer is, as described above, a single film formed from alayer obtained by the hydrolysis and condensation polymerization of ametal alkoxide or a crosslinked polymer layer comprising a thermosettingresin or a radiation-curable resin, a film formed from a layer obtainedby the hydrolysis and condensation polymerization of a mixturecomprising a metal oxide ultrafine particle and/or a metal fluorideultrafine particle and a metal alkoxide, or a film formed by thecrosslinking polymerization of a mixture of a metal oxide ultrafineparticle and/or a metal fluoride ultrafine particle with a thermosettingresin or a radiation-curable resin. The thickness of the film formed ispreferably from 15 to 100 nm, more preferably from 20 to 70 nm. Therefractive index of the high refractive-index layer is larger than therefractive index of the low refractive-index layer and the difference inthe refractive index is preferably 0.2 or more, more preferably 0.25 ormore.

[0089] The low refractive-index layer constituting the opticalinterference layer is, as described above, a single film formed from alayer obtained by the hydrolysis and condensation polymerization of ametal alkoxide or a crosslinked polymer layer comprising a thermosettingresin or a radiation-curable resin, a film formed from a layer obtainedby the hydrolysis and condensation polymerization of a mixturecomprising a metal oxide ultrafine particle and/or a metal fluorideultrafine particle and a metal alkoxide, or a film formed by thecrosslinking polymerization of a mixture of a metal oxide ultrafineparticle and/or a metal fluoride ultrafine particle with a thermosettingresin or a radiation-curable resin. The thickness of the film formed ispreferably 15 to 100 nm, more preferably from 20 to 70 nm. Therefractive index of the low refractive-index layer is preferably 1.6 orless.

[0090] When a layer obtained by the hydrolysis and condensationpolymerization of a metal alkoxide or a crosslinked polymer layercomprising a thermosetting resin or a radiation-curable resin is used asthe high refractive-index layer and the low refractive-index layer, thisis advantageous in view of cost, however, both an excellent opticalinterference effect (desired transparency and difference in therefractive index) and an excellent writing durability can hardly beattained at the same time. According to the present invention, not onlyis a crosslinked polymer layer used as the high refractive-index layerand the low refractive-index layer but also the above-describedultrafine particle is added to at least one of the high refractive-indexlayer and the low refractive-index layer, preferably to the highrefractive-index layer, preferably by controlling the amount added,whereby an optical interference layer having both a good opticalinterference effect and a good writing durability can be formed withoutcausing whitening of the film.

[0091] In the case where the low refractive-index layer is composed of acrosslinked polymer comprising a radiation-curable resin or athermosetting resin, it is preferred that the high refractive-indexlayer contains an ultrafine particles A and fine particles B (describedlater) in accordance with the present invention and that the lowrefractive-index layer does not contain fine particles (ultrafineparticle A and fine particle B).

[0092] (1e) Suitable Combination of High Refractive-Index Layer and LowRefractive-Index Layer

[0093] In one preferred embodiment of the present invention, the opticalinterference layer comprises a high refractive-index layer and a lowrefractive-index layer, the low refractive-index layer is in contactwith the transparent electroconductive layer, the low refractive-indexlayer comprises a layer obtained by hydrolysis and condensationpolymerization of silicon alkoxide, the high refractive-index layercomprises a layer obtained by hydrolysis and condensation polymerizationof a metal alkoxide mainly comprising a metal alkoxide other thanalkoxysilane, and the high refractive-index layer contains an ultrafineparticle comprising a metal oxide. To obtain the high refractive-indexlayer a metal alkoxide other than alkoxysilane is used, as the maincomponent of the metal alkoxide, and the high refractive-index layercontains an ultrafine particle, whereby a high refractive index can bemaintained and the transparent electroconductive laminate can have goodwriting durability.

[0094] Examples of the metal alkoxide other than alkoxysilane includetitanium alkoxide and zirconium alkoxide. Specific examples of thetitanium alkoxide and zirconium alkoxide are described above.

[0095] The content of the metal alkoxide other than alkoxysilane, whichis used as the main component of the metal alkoxide, is preferably from50 to 100%, more preferably from 70 to 100%. In practice, the content issuitably determined based on the use ratio at the time of preparing thecoating solution of the metal alkoxide.

[0096] The ultrafine particle for use in the high refractive-index layeris preferably a metal oxide ultrafine particle, for example, a metaloxide ultrafine particle selected from Bi₂O₃, CeO₂, In₂O₃, In₂O₃.SnO₂,HfO₂, La₂O₃, Sb₂O₅, Sb₂O₅.SnO₂, SnO₂, TiO₂, Y₂O₃, ZnO and ZrO₂. Theultrafine particles can be used individually or in combination of two ormore thereof.

[0097] By employing such a combination, the difference in therefractive-index can be made large while maintaining excellent adhesionbetween layers. The difference in the refractive-index is preferably atleast 0.1 or more, more preferably 0.2 or more, more preferably 0.25 ormore.

[0098] The weight ratio of the metal oxide ultrafine particle to themetal alkoxide is preferably from 1:99 to 60:40, more preferably from5:95 to 50:50.

[0099] This high refractive-index layer can be formed by the same methodas the method described above for forming a mixture of a metal alkoxideand ultrafine particles.

[0100] The low refractive-index layer used in combination with the highrefractive-index layer is a layer formed by hydrolysis and condensationpolymerization of alkoxysilane and this layer can also be formed asdescribed above. This low refractive-index layer may also containultrafine particles, if desired.

[0101] The high refractive-index layer and the low refractive-indexlayer each preferably has the above-described film thickness andrefractive index.

[0102] (1e) Second Fine Particle B (for Surface Roughening)

[0103] As described above, if the transparent electroconductive layersurface is roughened by adding, into a cured resin layer, a fineparticle having an average primary diameter larger than the cured resinlayer so as to prevent malfunctions of a transparent touch panel due toa sticking phenomenon of two transparent electroconductive layersurfaces of the movable electrode substrate and the fixed electrodesubstrate, the display grade of a high resolution color liquid crystaldisplay decreases on viewing it through the transparent touch panel.

[0104] The present inventors have found that when for roughening thetransparent electroconductive layer surface, a fine particle(hereinafter sometimes referred to as a fine particle B) is added to atleast one of the high refractive-index layer and the lowrefractive-index layer constituting the optical interference layer andhaving a thickness smaller than that of the cured resin layer, thetransparent electroconductive layer surface can be roughened even byusing a fine particle having an average primary diameter smaller thanthat of the fine particle added to the cured resin layer.

[0105] It has been also found that by controlling the average primarydiameter and amount of the fine particle added, the transparentelectroconductive layer surface can be roughened within the range of notcausing glare due to scattering of RGB three primary-color lights comingout of the liquid crystal display. It has been confirmed that when atransparent touch panel using a transparent electroconductive laminate,with a transparent electroconductive layer surface roughened, isdisposed on a high resolution color liquid crystal display and theliquid crystal display is viewed through the transparent touch panel,the display grade is good and is equal to the case where a transparenttouch panel using a conventional transparent electroconductive laminatecontaining substantially no fine particle in the cured resin layer andhaving a flat transparent electroconductive layer surface is disposed ona high resolution color liquid crystal display.

[0106] It has been also confirmed that a transparent touch panel using atransparent electroconductive laminate with the transparentelectroconductive layer surface being roughened by adding a fineparticle to at least one of the high refractive-index layer and the lowrefractive-index layer constituting the optical interference layer doesnot bring about malfunctions due to a sticking phenomenon between twotransparent electroconductive layers of the movable electrode substrateand the fixed electrode substrate.

[0107] As a result, according to a second aspect of the presentinvention, a transparent electroconductive layer and a transparent touchpanel can be provided, where the display grade does not decrease when atransparent touch panel is disposed on a high resolution color liquidcrystal display and the liquid crystal display is observed through thetransparent touch panel, malfunctions due to a sticking phenomenonbetween two transparent electroconductive layer surfaces of the movableelectrode substrate and the fixed electrode substrate constituting thetransparent touch panel are not caused, and high reliability can beensured in the writing durability and the like required of thetransparent touch panel.

[0108] Furthermore, the amount of the fine particle B added to at leastone of the high refractive-index layer and the low refractive-indexlayer constituting the optical interference layer is controlled to 0.5wt % or less of the crosslinked polymer, preferably metal alkoxidecomponent, constituting the layer to which the fine particle B is added,whereby a good optical interference layer, free from white turbidity,can be formed without impairing the effect of preventing malfunctions ofthe touch panel due to a sticking phenomenon between two transparentelectroconductive layer surfaces of the movable electrode substrate andthe fixed electrode substrate.

[0109] When the fine particle B is excessively added to at least one ofthe high refractive-index layer and the low refractive-index layerconstituting the optical interference layer, the fine particle addedreadily falls off or the adhesion between the optical interference layerand the cured resin layer decreases and the reliability in writingdurability required of the touch panel may be impaired. The fineparticle B is preferably contained only in the high refractive-indexlayer or in both the high refractive-index layer and the lowrefractive-index layer.

[0110] The fine particle B added to at least one of the highrefractive-index layer and the low refractive-index layer constitutingthe optical interference layer of the present invention may be either aninorganic material or an organic material and is not particularlylimited on the refractive index (preferably close to the refractiveindex of the high refractive-index layer and the low refractive-indexlayer). Examples thereof include a silica fine particle, a crosslinkedacryl fine particle and a crosslinked polystyrene fine particle.

[0111] The average primary diameter of the fine particle B is as largeas 1.1 times or more the film thickness of the optical interferencelayer and at the same time, the average primary diameter is 1.2 μm orless. If the average primary diameter of the fine particle is less than1.1 times the film thickness of the optical interference layer, thetransparent electroconductive layer surface can be hardly roughened.Also, if the average primary diameter of the fine particle exceeds 1.2μm, when a transparent touch panel using a transparent electroconductivelaminate containing such a fine particle in at least one of the highrefractive-index layer and the low refractive-index layer constitutingthe optical interference layer is disposed on a high resolution colorliquid crystal display and the liquid crystal display is viewed throughthe transparent touch panel, the liquid crystal display glares and thedisplay grade decreases. Furthermore, if the average primary diameter ofthe fine particle exceeds 1.2 μm, the average primary diameter is muchlarger than the film thickness of the optical interference layer towhich the fine particle is added, therefore, the fine particle addedreadily falls off from the optical interference layer and thereliability in writing durability or the like required of thetransparent touch panel can be hardly ensured.

[0112] The optical interference layer comprises at least one highrefractive-index layer and at least one low refractive-index layer andmay comprise two or more combination units of a high refractive-indexlayer and a low refractive-index layer. In the case where the opticalinterference layer consists of one high refractive-index layer and onelow refractive-index layer, the thickness of the optical interferencelayer is preferably from 30 to 150 nm, more preferably from 50 to 150nm. The average primary diameter of the fine particle B added to atleast one of the high refractive-index layer and the lowrefractive-index layer constituting the optical interference layer is1.1 times or more the film thickness of the optical interference layerand at the same time, 1.2 μm or less, preferably from 0.3 to 1.2 μm,more preferably from 0.5 to 1.0 μm.

[0113] In the optical interference layer, particularly, in the highrefractive-index layer, fine particles A (above-described ultrafineparticle) comprising a metal oxide and/or a metal fluoride and having anaverage primary diameter of 100 nm or less may be added individually orin combination of two or more in an appropriate amount as in the caseabove (first aspect of the present invention) for the purpose ofadjusting the refractive index but may not be added.

[0114] In the case of adding the fine particle A to the opticalinterference layer, the weight ratio of the fine particle A to the metalalkoxide is preferably from 0:100 to 60:40, more preferably from 0:100to 80:20, still more preferably from 0:100 to 40:60. If the weight ratioof the fine particles B to the metal alkoxide exceeds 80:20, thestrength or adhesive property necessary for the optical interferencelayer may be insufficient and this it not preferred.

[0115] Other matters regarding this fine particle A are the same asthose described above for the ultrafine particle.

[0116] (2) Cured Resin Layer

[0117] In the transparent electroconductive laminate of the presentinvention, a cured resin layer may be formed between the opticalinterference layer and the organic polymer film. The cured resin layeris a layer capable of contributing to the improvement of abrasionresistance, flexibility and the like. As the material for forming thiscured resin layer, a curable resin such as a thermosetting resin and aradiation-curable resin (for example, curable with ultraviolet light)can be used. Specific examples of the curable resin include anorganosilane-base thermosetting resin starting frommethyltriethoxysilane, phenyltriethoxysilane or the like, amelamine-base thermosetting resin starting from etherifiedmethylolmelamine or the like, and a polyfunctional acrylate-baseultraviolet-curable resin starting from polyol acrylate, polyesteracrylate, urethane acrylate, epoxy acrylate or the like.

[0118] In this cured resin layer, the surface where the opticalinterference layer is usually stacked may be rich in the flatness or maybe roughened. In the case of roughening the surface, for example, asilica fine particle may be incorporated into the cured resin layer.However, in using the second aspect of the present invention, thesurface where the optical interference layer is stacked need not beroughened and is preferably flat. More specifically, in using the secondaspect of the present invention, the cured resin layer present betweenthe optical interference layer and the organic polymer film in thetransparent electroconductive laminate of the present inventionpreferably contains substantially no fine particles. If a particle sizehaving an average primary diameter larger than the film thickness of thecured resin layer is added in the cured resin layer, this may provide aneffect of preventing malfunctions of the transparent touch panel due toa sticking phenomenon between two transparent electroconductive layersurfaces of the movable electrode substrate and the fixed electrodesubstrate, but there arises a problem that the display grade of a highresolution color liquid crystal display decreases when observed throughthe transparent touch panel. Furthermore, if a fine particle having anaverage primary diameter smaller than the film thickness of the curedresin layer is added, not only an effect of preventing malfunctions ofthe transparent touch panel due to the above-described stickingphenomenon is not provided but also, depending on the size of the fineparticle, there arises a similar problem that the display grade of ahigh resolution color liquid crystal display decreases when observedthrough the transparent touch panel. However, the cured resin layer maycontain a fine particle in the range of not inhibiting the display gradeof a high resolution color liquid crystal display when observed throughthe transparent touch panel.

[0119] For the purpose of preventing the generation of interferencefringe between the movable electrode substrate and the fixed electrodesubstrate, a protrusion is preferably formed on the transparentelectroconductive layer surface. The surface shape preferred forpreventing the generation of interference fringe is such that theaverage protrusion height is from 0.3 to 1 μm and the protrusion densityis from 350 to 1,800 pieces/mm². When a transparent electroconductivelaminate comprising a cured resin layer having a surface shaped as suchis used for the movable electrode substrate and/or the fixed electrodesubstrate of the touch panel, an interference fringe is not generatedbetween two transparent electroconductive layers even when the movableelectrode substrate is warped to come close to the fixed electrodesubstrate, and therefore, the display can be clearly viewed. If theaverage protrusion height is less than 0.3 μm or the protrusion densityis less than 350 pieces/mm², the effect of preventing the generation ofinterference fringe is small. On the other hand, if the averageprotrusion height exceeds 1 μm, the pen writing durabilitydisadvantageously decreases. Furthermore, if the protrusion densityexceeds 1,800 pieces/mm², the haze of the transparent electroconductivelaminate increases to cause a problem that the letter on the display isblurred and cannot be clearly viewed. Of course, when the purpose isonly to prevent sticking, the average protrusion height may be less than0.3 μm or the protrusion density may be less than 350 pieces/mm².

[0120] Here, the average protrusion height and the protrusion densitywere determined as follows. Using a real time scanning laser microscope(1LM21D, manufactured by Lasertec Corporation), from 10 to 20protrusions were selected at random within a 250 μm-square visual fieldand after measuring the height of each protrusion, the averageprotrusion height was calculated. Also, from the number of protrusionsin the same visual field, the protrusion density (the number ofprotrusions per unit area) was calculated.

[0121] The thickness of the cured resin layer is preferably from 2 to 5μm in view of flexibility and friction durability.

[0122] The cured resin layer can be formed by a coating method. Inpractical coating, the above-described compound and various additives(e.g., curing agent, catalyst) are dissolved in an organic solvent ofvarious types and after adjusting the concentration or viscosity, theobtained coating solution is coated on an organic polymer film.Thereafter, the layer is cured by irradiating a radiation or applying aheat treatment. Examples of the coating method include various coatingmethods such as microgravure coating method, Mayer bar coating method,direct gravure coating method, reverse roll coating method, curtaincoating method, spray coating method, comma coating method, die coatingmethod, knife coating method, spin coating method, doctor knife methodand dipping method.

[0123] The thickness of the cured resin layer is preferably from 2 to 5μm in view of flexibility and friction resistance.

[0124] The cured resin layer is stacked on an organic polymer filmdirectly or through an appropriate anchor layer. Preferred examples ofthe anchor layer include a layer having a function of improving theadhesion between the cured resin layer and the organic polymer film,various phase compensating layers such as layer having athree-dimensional refractive index property of giving a negative K value(K={(n_(x)+n_(y))/2−n_(z)}×d, wherein n_(x), n_(y) and n_(z) representrefractive indices in the x-axis, y-axis and z-axis directions,respectively, the x-axis and y-axis are orthogonal axes in the filmplane and the z-axis is the film thickness direction), a layer having afunction of preventing permeation of water or air or a function ofabsorbing water or air, a layer having a function of absorbingultraviolet or infrared light, and a layer having a function ofdecreasing the electrostatic charging property of the substrate.

[0125] (3) Organic Polymer Film

[0126] The organic polymer compound constituting the organic polymerfilm for use in the present invention is not particularly limited aslong as it is a transparent organic polymer having excellent heatresistance. Examples thereof include a polyester-base resin (e.g.,polyethylene terephthalate, polyester-2,6-naphthalate, polydiallylphthalate), a polycarbonate resin, a polyethersulfone resin, apolysulfone resin, a polyarylate resin, an acrylic resin, a celluloseacetate resin, a cyclic polyolefin and a norbornene resin. Needless tosay, these may be used as a homopolymer or a copolymer or may be usedindividually or as a blend. Furthermore, two or more sheets of theorganic polymer film formed from such a resin may be laminated with eachother using a pressure-sensitive adhesive or the like and used as amultilayered organic polymer film.

[0127] In the case of using the transparent electroconductive laminateof the present invention as the movable electrode substrate of atransparent touch panel, the substrate shape of the organic polymer filmis preferably a film form having a thickness of 75 to 400 μm in view ofthe strength to maintain the flexibility and flatness for actuating thetransparent touch panel as a switch. In the case of use as the fixedelectrode substrate, a sheet form having a thickness of 0.4 to 4.0 mm ispreferred in view of the strength to maintain the flatness, however, afilm form having a thickness of 50 to 400 μm may also be used bylaminating it with another sheet to have an entire thickness of 0.4 to4.0 mm.

[0128] In the case of using the transparent electroconductive laminateof the present invention as the movable electrode substrate of atransparent touch panel, the fixed electrode substrate may be producedby forming a transparent electroconductive layer on the above-describedorganic polymer film substrate, a glass substrate or a laminatesubstrate thereof. In view of the strength and weight of the transparenttouch panel, the thickness of the fixed electrode substrate comprising asingle layer or a laminate is preferably from 0.4 to 2.0 mm.

[0129] In recent years, a new transparent touch panel having aconstitution that a polarizer or (a polarizer+a retardation film) isstacked in the input side (user side) of the transparent touch panel hasbeen developed. This constitution is advantageous in that thereflectance of extraneous light inside the transparent touch panel isreduced to a half or less mainly by the optical action of the polarizeror the polarizer+the retardation film) and the contrast of the displayis improved when observed through the transparent touch panel.

[0130] In the transparent touch panel of this type, the polarized lightpasses through the transparent electroconductive laminate and,therefore, the organic polymer film used preferably has excellentoptical isotropy. More specifically, assuming that the refractive indexin the slow axis direction is n_(x), the refractive index in the fastaxis direction is n_(y) and the thickness of the substrate is d (nm),the in-plane retardation value Re represented by Re=(n_(x)−n_(y))×d (nm)is preferably at least 30 nm or less, more preferably 20 nm or less.Here, the in-plane retardation value of the substrate is represented bythe value at a wavelength of 590 nm measured using a spectroellipsometer(M-150 manufactured by JASCO Corporation).

[0131] In uses of this type of transparent touch panel where polarizedlight passes through the transparent electroconductive laminate, thein-plane retardation value of the transparent electrode substrate isvery important. In addition, the transparent electrode substratepreferably has a three-dimensional refractive index property, morespecifically, assuming that the refractive index in the film thicknessdirection of the substrate is n_(z), the K value represented byK={(n_(x)+n_(y))/2−n_(z)}×d is from −250 to +150 nm and for obtaining anexcellent view an angle property of the transparent touch panel, morepreferably from −200 to +100 nm.

[0132] Examples of the organic polymer film exhibiting excellentproperties in the optical isotropy include a casted substrate of apolycarbonate, an amorphous polyarylate, a polyethersulfone, apolysulfone, a triacetyl cellulose, a diacetyl cellulose, an amorphouspolyolefin or their modified product or copolymer with a different kindof material; a casted substrate of a thermosetting resin such asepoxy-base resin; and a casted substrate of an ultraviolet-curable resinsuch as acrylic resin. In view of castability, production cost, thermalstability and the like, a casted substrate of a polycarbonate, anamorphous polyarylate, a polyethersulfone, a polysulfone, an amorphouspolyolefin or their modified product or copolymer with a different kindof material is most preferred.

[0133] More specifically, examples of the polycarbonate casted substratepreferably used include a casted substrate of a polycarbonate having anaverage molecular weight of approximately from 15,000 to 100,000(examples of the commercial product include “PURE ACE” produced byTeijin Ltd., “PANLIGHT” produced by Teijin Chemicals Ltd., and “Apec HT”produced by Bayer), which is a polymer or copolymer using, as themonomer unit, at least one component selected from the group consistingof bisphenol A, 1,1-di-(4-phenol)cyclohexylidene,3,3,5-trimethyl-1,1-di(4-phenol)cyclohexylidene,fluorene-9,9-di(4-phenol) and fluorene-9,9-di(3-methyl-4-phenol), or amixture thereof.

[0134] Examples of the amorphous polyarylate casted substrate includecasted substrates of, as the commercial product, “ELMECK” produced byKanegafuchi Chemical Industry Co., Ltd., “U POLYMER” produced by UnitikaLtd., and “ISARYL” produced by Isonova.

[0135] Examples of the amorphous polyolefin casted substrate includecasted substrates of, as the commercial product, “ZEONOR” produced byZEON Corporation, and “ARTON” produced by JSR.

[0136] Examples of the method for casting the polymer material include amelt extrusion method, a solution casting method and an injectionmolding method, however, from the standpoint of obtaining excellentoptical isotropy, the polymer material is preferably casted by thesolution casting method.

[0137] (4) Transparent Electroconductive Layer

[0138] In the present invention, a transparent electroconductive layeris stacked on the low refractive-index layer to come into contact withthe layer. By stacking a transparent electroconductive layer to comeinto contact with the low refractive-index layer, the optical propertiesand mechanical properties such as writing durability of the transparentelectroconductive laminate are improved. Examples of the transparentelectroconductive layer include an ITO film containing from 2 to 20 wt %of tin oxide, and a tin oxide film doped with antimony, fluorine or thelike. Examples of the method for forming the transparentelectroconductive layer include a PVD method such as sputtering, vacuumevaporation and ion plating, a coating method, a printing method and aCVD method. Among these, a PVD method and a CVD method are preferred. Inthe case of the PVD method or the CVD method, the thickness of thetransparent electroconductive layer is preferably from 5 to 50 nm inview of transparency and electric conductivity. The transparentelectroconductive layer is preferably a film mainly comprising acrystalline indium oxide, more preferably a film mainly comprising acrystalline indium oxide having a crystal grain size of 2,000 nm orless. If the crystal grain size exceeds 2,000 nm, the pen writingdurability is worsened and this is not preferred. In view of stabilityof optical properties and resistance value, the thickness is morepreferably from 12 to 30 nm. If the thickness of the transparentelectroconductive layer is less than 12 nm, the resistance value isliable to have poor aging stability, whereas if it exceeds 30 nm, thetransmittance of the transparent electroconductive laminate decreasesand this is not preferred. In view of reduction in the power consumptionof the touch panel or necessity in the circuit processing, a transparentelectroconductive layer showing a surface resistance value of 100 to2,000 Ω/□ (Ω/square), more preferably from 140 to 2,000 Ω/□ (Ω/square),with the thickness of 12 to 30 nm is preferably used.

[0139] In the layer mainly comprising a crystalline indium oxide, one ormore metal oxide such as tin oxide, silicon oxide, titanium oxide,aluminum oxide, zirconium oxide and zinc oxide may be added so as toimprove the transparency or adjust the surface resistance value or thelike. In particular, a crystalline indium tin oxide (ITO) is preferredbecause of its excellent transparency and electric conductivity.

[0140] As one example of the method for obtaining a layer mainlycomprising a crystalline indium oxide having a crystal grain size of2,000 nm or less, a method for obtaining a crystalline indium tin oxidefilm is described below. First, an amorphous indium tin oxide filmcontaining microcrystal is stacked by using a known PVD method such assputtering, ion plating or vacuum evaporation. Then, an annealingtreatment is performed at a temperature of 100 to 150° C. to grow thecrystal from the microcrystal. Depending on the deposition conditions bythe PVD method, for example, a film where the crystal grain size isdistributed in the range from a minimum grain size of 10 nm to a maximumgrain size of 300 nm, or a film where the crystal grain size isdistributed in the range from a minimum grain size of 250 nm to amaximum grain size of 2,000 nm is obtained. When such a film is used asthe transparent electroconductive layer of the present invention, thepen writing durability is improved. From this, it is presumed that thestress imposed on the transparent electroconductive layer at the writingwith a pen is relieved at the grain boundary due to the film structurewhere the crystal grain size is distributed, and the film strength ofthe transparent electroconductive layer itself is improved. The crystalgrain size as used herein is defined as a largest size among diagonallines or diameters in the polygonal or elliptic region observed througha transmission-type electron microscope.

[0141] (5) Cured Resin Layer on Another Surface

[0142] In the case of using the transparent electroconductive laminateof the present invention as the movable electrode substrate, a curedresin layer is preferably stacked on the surface where, in a transparenttouch panel, an external force is applied. Examples of the material forforming the cured resin layer include an organosilane-base thermosettingresin starting from methyltriethoxysilane, phenyltriethoxysilane or thelike, a melamine-base thermosetting resin starting from etherifiedmethylolmelamine or the like, and a polyfunctional acrylate-baseultraviolet-curable resin starting from polyol acrylate, polyesteracrylate, urethane acrylate, epoxy acrylate or the like. If desired, asilica ultrafine particle or the like may be mixed. The thickness of thecured resin layer is preferably from 2 to 5 μm in view of flexibilityand friction durability.

[0143] (6) Intermediate Layer

[0144] In the transparent electroconductive laminate of the presentinvention, an intermediate layer such as adhesive layer may be stackedbetween respective layers constituting the transparent electroconductivelaminate, that is, between the organic polymer film and the cured resinlayer and between the cured resin layer and the optical interferencelayer, as far as it does not impair the object of the present invention.

[0145] For example, the cured resin layer is stacked on the organicpolymer film directly or through an appropriate anchor layer. Preferredexamples of the anchor layer include a layer having a function ofimproving the adhesion between the cured resin layer and the organicpolymer film, various phase compensating layers such as layer having athree-dimensional refractive index property of giving a negative Kvalue, a layer having a function of preventing permeation of water orair or a function of absorbing water or air, a layer having a functionof absorbing ultraviolet or infrared light, and a layer having afunction of decreasing the electrostatic charging property of thesubstrate.

[0146] (7) Multilayer-Type Organic Polymer Film Substrate

[0147] In the case of using the transparent electroconductive laminateof the present invention as the movable electrode substrate of a touchpanel, a constitution where a transparent substrate is stacked on thesurface of the organic polymer film opposite the transparentelectroconductive layer, through a transparent elastic layer having aYoung's modulus lower than that of the organic polymer film may beemployed so as to improve the finger touching durability, pen writingdurability and reliability in a high-temperature or high-temperaturehigh-humidity environment of the touch panel.

[0148]FIG. 2 shows a constitution example of a transparentelectroconductive laminate in this embodiment. In FIG. 2, the samemembers as in FIG. 1 are shown by the same reference numbers as in FIG.1, that is, the members are an organic polymer film 1, a cured resinlayer 2, a high refractive-index layer 3, a low refractive-index layer4, a transparent electroconductive layer 5 and a cured resin layer 6. Inthis embodiment, the substrate film is constituted such that atransparent elastic layer 7 is interposed between the organic polymerfilm 1 and the transparent base material 8 and, on both surfacesthereof, a cured resin layer 2 or 6 is stacked.

[0149] The transparent elastic layer suitably used in the presentinvention is preferably a material having high transparency, being lowin the Young's modulus than the transparent polymer film, and capable ofexhibiting good adhesive property both to the transparent polymer filmand the transparent substrate. For buffering the impact a writing with apen, the Young's modulus of the transparent elastic layer must berendered smaller than the Young's modulus of the transparent polymerfilm. However, if the Young's modulus is extremely small, thetransparent elastic layer adheres to a blade in the process such aspunching out or slitting of the transparent electroconductive laminateand this disadvantageously gives rise to a foreign particle defect. TheYoung's modulus is preferably from about ⅕th to {fraction (1/80)}th ofthe Young's modulus of the transparent polymer film. For example, whenthe transparent polymer film is a polyethylene terephthalate film, theYoung's modulus of the transparent elastic layer is from 7×10⁷ to 1×10⁹Pa.

[0150] The Young's modulus of the transparent elastic layer is measuredby a nano indentation tester (ENT-1100a, manufactured by Elionix). Atriangular pyramid-shaped indenter (angle between edges: 115°, diamond)is pressed into the surface of the transparent elastic layer (in theside opposite the transparent polymer film) to a depth of 0.5 μm under aload of 15 mgf (147 μN) and from the gradient of the graph on removingthe load, the Young's modulus is calculated.

[0151] The thickness of the transparent elastic layer is from 5 to 45μm, preferably from 10 to 40 μm. If the thickness is less than 5 μm, theeffect of buffing the impact a writing with a pen is small, whereas ifit exceeds 45 μn, the transparent elastic layer adheres to a blade inthe process such as punching out or slitting of the transparentelectroconductive laminate and this disadvantageously gives rise to aforeign particle defect.

[0152] Examples of the material used for the transparent elastic layerinclude a polyester-base resin, an acryl-base resin, a polyurethane-baseresin, an epoxy-base resin and a silicone-base resin. Among these, asilicone-base resin is preferred because the Young's modulus is lesschanged in the process of manufacturing a touch panel or when left standin a high-temperature environment.

[0153] (8) Touch Panel

[0154] In a transparent touch panel where two sheets of transparentelectrode substrates each having stacked on at least one surface thereofa transparent electroconductive layer are disposed such that thetransparent electroconductive layers face each other, the transparentelectroconductive laminate of the present invention can be used as atleast one sheet of the transparent electrode substrates. This is morespecifically described in Examples later.

[0155]FIG. 3 shows a constitution example of a touch panel using thetransparent electroconductive laminate of the present invention.

[0156] The transparent electroconductive laminate P or R shown in FIG. 1or 2 is used as one electrode substrate. In FIG. 3, the transparentelectroconductive laminate R of FIG. 2 is used as the movable electrodesubstrate and a fixed electrode substrate F where a transparentelectroconductive layer 10 is formed on the surface of a glass substrate9 and dot spacers 11 are further formed on the surface thereof isdisposed to face the transparent electroconductive layer 5, therebyfabricating a touch panel. The space between the movable electrodesubstrate R and the fixed electrode substrate F is usually set to 10 to100 μm using a spacer (not shown). When the surface of the movableelectrode substrate is touched with a finger or a pen, the movableelectrode substrate R and the fixed electrode substrate F are put intocontact with each other at the touched position and therefore, the inputposition can be detected due to the potential difference. The dot spacer11 prevents the movable electrode substrate R from warping to come intocontact by a natural force with the fixed electrode substrate, but thisis formed to enable the input with a finger or a pen and is notessential.

[0157]FIG. 4 shows an example where a touch panel is fixed on a liquidcrystal display device. In FIG. 4, a touch panel 15 comprising a movableelectrode substrate 13 and a fixed electrode substrate 14, which arefacing each other, is disposed on a liquid crystal display device 23.The liquid crystal display device 23 is typically constituted such thata liquid crystal layer 19 is interposed between two glass substrates 17and 21 each having stacked on the inside surface thereof a transparentelectrode 18 or 20 and in the outer side of each glass substrate 17 or21, a polarizer 16 or 22 is disposed. Of course, the specificconstitution of the liquid crystal display device is not limited to thisexample and a constitution example where, for example, the polarizer isnot disposed in the liquid crystal display device but in the touchpanel, may be employed.

EXAMPLES

[0158] The present invention is described in greater detail below,however, the present invention is not limited thereto.

[0159] In the following Examples, the linearity, Young's modulus andaverage primary diameter were measured as follows.

[0160] Linearity

[0161] A d.c. voltage of 5 V was applied between parallel electrodes onthe movable electrode substrate or on the fixed electrode substrate. Thevoltage was measured at intervals of 5 mm in the direction perpendicularto the parallel electrodes. Assuming that the voltage at the measurementstart point A is EA, the voltage at the measurement finish point B isEB, the measured voltage value at a distance X from A is EX, thetheoretical value is ET and the linearity is L,

[0162] ET=(EB−EA)·X(B−A)+EA

[0163] L (%)=(|ET−EX|)/(EB−EA)×100

[0164] Young's Modulus

[0165] The Young's modulus was measured by a nano indentation tester(ENT-1100a, manufactured by Elionix). A triangular pyramid-shapedindenter (angle between edges: 115°, diamond) was pressed into thesurface of the transparent elastic layer to a depth of 0.5 μm under aload of 15 mgf (1.47 μN) and from the gradient of the graph on removingthe load, the Young's modulus was calculated.

[0166] Average Primary Diameter of Fine Particle

[0167] The average primary diameter was measured using a laserscattering particle size distribution analyzer.

Example 1

[0168] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material.

[0169] γ-glycidoxypropyltrimethoxysilane (“KBM403”, produced byShin-Etsu Chemical Co., Ltd.) and methyltrimethoxysilane (“KBM13”,produced by Shin-Etsu Chemical Co., Ltd.) were mixed at a molar ratio of1:1 and this silane was hydrolyzed by a known method using an aqueousacetic acid solution (pH=3.0). To the thus-obtained hydrolysate ofsilane, N-β(aminoethyl)γ-aminopropylmethoxysilane (“KBM603”, produced byShin-Etsu Chemical Co., Ltd.) was added at a weight ratio of 20:1 as asolid content. The resulting solution was diluted with a mixed solutionof isopropyl alcohol and n-butanol to prepare Alkoxysilane CoatingSolution A.

[0170] Thereafter, a ZnO fine particle having a primary diameter of 20nm was mixed in Coating Solution A to prepare Coating Solution B wherethe weight ratio of ZnO fine particle to alkoxysilane was 75:25. CoatingSolution B was coated on the PET surface opposite the cured resin layer(1) by a bar coating method and baked at 130° C. for 2 minutes to form ahigh refractive-index layer having a thickness of 70 nm. Subsequently,Coating Solution A was coated on the high refractive-index layer by abar coating method and baked at 130° C. for 2 minutes to form a lowrefractive-index layer having a thickness of 45 nm, thereby producing anoptical interference layer consisting of a high refractive-index layerand a low refractive-index layer. Furthermore, an ITO layer was formedon the low refractive-index layer by a sputtering method using anindium-tin oxide target having a composition of indium oxide and tinoxide in a weight ratio of 9:1 and having a packing density of 98%, toproduce a transparent electroconductive laminate for use as a movableelectrode substrate. The transparent electroconductive laminate afterthe ITO layer formation had the total luminous transmittance of 91.3%and a haze value of 2.4%.

[0171] Separately, SiO₂ was dip-coated on both surfaces of a 1.1mm-thick glass plate and thereon, an ITO layer having a thickness of 18nm was formed in the same manner as above by the sputtering method. Onthis ITO layer, dot spacers with a height of 7 μm, a diameter of 70 μmand a pitch of 1.5 mm were formed to produce a fixed electrodesubstrate. Using these fixed electrode substrate and movable electrodesubstrate thus produced, a transparent touch panel shown in FIG. 5 wasproduced. A writing durability test of reciprocating straight lines300,000 times under a load of 250 g was performed using apolyacetal-made pen having a tip of 0.8R from the movable electrode sideof the produced transparent touch panel. After the writing durabilitytest, the electrical property (linearity) of the transparent touch panelwas measured and the appearance of the optical interference layer wasobserved. The results are shown in Table 1.

Example 2

[0172] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. Then, on the opposite surface, a curedresin layer (2) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material where asilica particle having an average primary diameter of 4.0 μm was mixedin a ratio of 0.1 part by weight per 100 parts by weight of the resinsolid content. Incidentally, in the following Examples, when a silicaparticle was mixed in the cured resin layer, this constitution was usedin all cases.

[0173] An SnO₂ fine particle having a primary diameter of 50 nm wasmixed in Coating Solution A used in Example 1 to prepare CoatingSolution C where the weight ratio of SnO₂ fine particle to alkoxysilanewas 50:50. Coating Solution C was coated on the silicaparticle-containing cured resin layer (2) by a bar coating method andbaked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 70 nm. An MgF₂ fine particle having a primarydiameter of 90 nm was mixed in Coating Solution A used in Example 1 toprepare Coating Solution D where the weight ratio of MgF₂ fine particleto alkoxysilane was 10:90. Coating Solution D was coated on the highrefractive-index layer by a bar coating method and baked at 130° C. for2 minutes to form a low refractive-index layer having a thickness of 50nm, thereby producing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer. Furthermore, anindium tin lower oxide layer was formed on the low refractive-indexlayer by a reactive sputtering method using, as the sputtering target,an indium-tin alloy target having a composition of indium and tin in aweight ratio of 9:1 and then heat-treated at 150° C. for 15 hours toform a crystalline ITO layer having a thickness of 19 nm and a surfaceresistance value of about 400 Ω/□ (about 400 Ω/square), whereby atransparent electroconductive laminate for use as a movable electrodesubstrate was produced. The transparent electroconductive laminate afterthe ITO layer formation had the total luminous transmittance of 90.2%and a haze value of 2.8%.

[0174] Using the produced movable electrode substrate and a glass fixedelectrode substrate with a transparent electroconductive layer producedin the same manner as in Example 1, a transparent touch panel shown inFIG. 5 was produced. A writing durability test of reciprocating straightlines 300,000 times under a load of 250 g was performed in the samemanner as in Example 1. The test results are shown in Table 1.

Example 3

[0175] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. Then, on the opposite surface, a curedresin layer (2) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material havingmixed therein a silica particle. A ZrO₂ fine particle having a primarydiameter of 60 nm was mixed in Coating Solution A used in Example 1 toprepare Coating Solution E where the weight ratio of ZrO₂ fine particleto alkoxysilane was 50:50. Coating Solution E was coated on the silicaparticle-containing cured resin layer (2) by a bar coating method andbaked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 70 nm. An Al₂O₃ fine particle having a primarydiameter of 20 nm was mixed in Coating Solution A used in Example 1 toprepare Coating Solution F where the weight ratio of Al₂O₃ fine particleto alkoxysilane was 15:85. Coating Solution F was coated on the highrefractive-index layer by a bar coating method and baked at 130° C. for2 minutes to form a low refractive-index layer having a thickness of 45nm, thereby producing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer. Furthermore, anITO layer was formed on the low refractive-index layer in the samemanner as in Example 2 to produce a transparent electroconductivelaminate for use as a movable electrode substrate. The transparentelectroconductive laminate after the ITO layer formation had the totalluminous transmittance of 89.8% and a haze value of 2.5%.

[0176] Separately, on both surfaces of a 75 μm-thick polyethyleneterephthalate film (OFW, produced by Teijin Ltd.), a cured resin layerhaving a thickness of 3 μm was formed using an ultraviolet-curableurethane acrylate resin coating material. Coating Solution E was coatedon the cured resin layer (2) on one surface by a bar coating method andbaked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 70 nm. Subsequently, Coating Solution F was coatedon the high refractive-index layer by a bar coating method and baked at130° C. for 2 minutes to form a low refractive-index layer having athickness of 45 nm, thereby producing an optical interference layerconsisting of a high refractive-index layer and a low refractive-indexlayer. Furthermore, an ITO layer was formed on the low refractive-indexlayer in the same manner as in Example 2 to produce a transparentelectroconductive laminate for use as a movable electrode substrate. Thetransparent electroconductive laminate after the ITO layer formation hadthe total luminous transmittance of 90.2% and a haze value of 1.5%.Using this transparent electroconductive laminate, a fixed electrodesubstrate was produced by attaching, using a pressure-sensitiveadhesive, a 1.1 mm-thick polycarbonate sheet to come into contact withthe surface opposite the surface where the ITO layer was formed, andthen forming dot spacers with a height of 7 μm, a diameter of 70 μm anda pitch of 1.5 mm on the ITO layer.

[0177] Using the produced movable electrode substrate and the producedfixed electrode substrate, a transparent touch panel shown in FIG. 6 wasproduced. A writing durability test of reciprocating straight lines300,000 times under a load of 250 g was performed in the same manner asin Example 1. The test results are shown in Table 1.

Example 4

[0178] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. Then, on the opposite surface, a curedresin layer (2) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material havingmixed therein a silica particle.

[0179] A TiO₂ fine particle having a primary diameter of 20 nm was mixedin Coating Solution A used in Example 1 to prepare Coating Solution Gwhere the weight ratio of TiO₂ fine particle to alkoxysilane was 50:50.Coating Solution G was coated on the silica particle-containing curedresin layer (2) by a bar coating method and baked at 130° C. for 2minutes to form a high refractive-index layer having a thickness of 40nm. Subsequently, Coating Solution A used in Example 1 was coated on thehigh refractive-index layer by a bar coating method and baked at 130° C.for 2 minutes to form a low refractive-index layer having a thickness of40 nm, thereby producing an optical interference layer consisting of ahigh refractive-index layer and a low refractive-index layer.Furthermore, an ITO layer was formed on the low refractive-index layerin the same manner as in Example 1 to produce a transparentelectroconductive laminate for use as a movable electrode substrate. Thetransparent electroconductive laminate after the ITO layer formation hadthe total luminous transmittance of 90.8% and a haze value of 2.2%.

[0180] Separately, on both surfaces of a 100 μm-thick polycarbonate film(PURE ACE, produced by Teijin Ltd.), a cured resin layer having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. The subsequent procedure was performedin the same manner as in the production of the movable electrodesubstrate above, that is, Coating Solution G was coated on the curedresin layer (2) on one surface by a bar coating method and baked at 130°C. for 2 minutes to form a high refractive-index layer having athickness of 40 nm, then Coating Solution A used in Example 1 was coatedon the high refractive-index layer by a bar coating method and baked at130° C. for 2 minutes to form a low refractive-index layer having athickness of 40 nm, thereby producing an optical interference layerconsisting of a high refractive-index layer and a low refractive-indexlayer, and furthermore, an ITO layer was formed on the lowrefractive-index layer to produce a transparent electroconductivelaminate. The transparent electroconductive laminate after the ITO layerformation had the total luminous transmittance of 90.5% and a haze valueof 2.3%. A 1.1 mm-thick polycarbonate sheet was attached using apressure-sensitive adhesive to this transparent electroconductivelaminate to come into contact with the surface opposite the surfacewhere the ITO layer was formed, and then dot spacers with a height of 7μm, a diameter of 70 μm and a pitch of 1.5 mm were formed on the ITOlayer, whereby a fixed electrode substrate was produced. Using theproduced movable electrode substrate and the produced fixed electrodesubstrate, a transparent touch panel shown in FIG. 6 was produced. Awriting durability test of reciprocating straight lines 300,000 timesunder a load of 250 g was performed in the same manner as in Example 1.The test results are shown in Table 1.

REFERENCE EXAMPLE

[0181] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. Then, on the opposite surface, a curedresin layer (2) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material havingmixed therein a silica particle. A TiO₂ fine particle having a primarydiameter of 20 nm was mixed in Coating Solution A used in Example 1 toprepare Coating Solution H where the weight ratio of TiO₂ fine particleto alkoxysilane was 90:10. Coating Solution H was coated on the silicaparticle-containing cured resin layer (2) by a bar coating method andbaked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 70 nm. Subsequently, Coating Solution A used inExample 1 was coated on the high refractive-index layer by a bar coatingmethod and baked at 130° C. for 2 minutes to form a low refractive-indexlayer having a thickness of 50 nm, thereby producing an opticalinterference layer consisting of a high refractive-index layer and a lowrefractive-index layer. Furthermore, an ITO layer was formed on the lowrefractive-index layer to produce a transparent electroconductivelaminate for use as a movable electrode substrate. The transparentelectroconductive laminate after the ITO layer formation had the totalluminous transmittance of 91.0% and a haze value of 2.7%.

[0182] Using the produced movable electrode substrate and a glass fixedelectrode substrate with a transparent electroconductive layer producedin the same manner as in Example 1, a transparent touch panel shown inFIG. 5 was produced. A writing durability test of reciprocating straightlines 300,000 times under a load of 250 g was performed in the samemanner as in Example 1. The results are shown in Table 1.

Comparative Example 1

[0183] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. Then, on the opposite surface, a curedresin layer (2) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material havingmixed therein a silica particle.

[0184] Coating Solution I was prepared by diluting tetrabutoxytitanate(“B-4” produced by Nippon Soda Co., Ltd.) with a mixed solvent ofligroin (produced by Wako Pure Chemical Industries, Ltd., guaranteedgrade) and butanol (produced by Wako Pure Chemical Industries, Ltd.,guaranteed grade). Subsequently, Coating Solution I was coated on thesilica particle-containing cured resin layer by a bar coating method andbaked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 75 nm. Thereafter, Coating Solution A used inExample 1 was coated on the high refractive-index layer by a bar coatingmethod and baked at 130° C. for 2 minutes to form a low refractive-indexlayer having a thickness of 45 nm, thereby producing an opticalinterference layer consisting of a high refractive-index layer and a lowrefractive-index layer. Furthermore, an ITO layer was formed on the lowrefractive-index layer in the same manner as in Example 1 to produce atransparent electroconductive laminate for use as a movable electrodesubstrate. The transparent electroconductive laminate after the ITOlayer formation had the total luminous transmittance of 89.5% and a hazevalue of 2.7%.

[0185] Using the produced movable electrode substrate and a glass fixedelectrode substrate with a transparent electroconductive layer producedin the same manner as in Example 1, a transparent touch panel shown inFIG. 5 was produced. A writing durability test of reciprocating straightlines 300,000 times under a load of 250 g was performed in the samemanner as in Example 1. The results are shown in Table 1. TABLE 1Durability by Writing Reciprocating Total Luminous Straight LinesTransmittance 300,000 Time Under (%) Haze (%) Load of 250 g Example 191.3 2.4 No change in both electric property and appearance. Example 290.2 2.8 No change in both electric property and appearance. Example 3movable movable No change in both electrode: 91.1 electrode: 2.4electric property and fixed fixed appearance. electrode: 90.8 electrode:1.7 Example 4 movable movable No change in both electrode: 89.8electrode: 2.5 electric property and fixed fixed appearance. electrode:90.2 electrode: 1.5 Reference 91.0 2.7 bad electric property Example andstripping of optical interference layer. Comparative 89.5 2.7 badelectric property Example 1 and stripping of optical interference layer

Example 5

[0186] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. Then, on the opposite surface, a curedresin layer (2) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material havingmixed therein a silica particle.

[0187] Subsequently, in a mixed solution of a metal alkoxide obtained bymixing Coating Solution I and Coating Solution A used in Example 1 tohave a Coating Solution I content of 80%, a ZnO fine particle having aprimary diameter of 20 nm was mixed to prepare Coating Solution J wherethe weight ratio of ZnO fine particles to metal alkoxide was 20:80.Coating Solution J was coated on the silica particle-containing curedresin layer (2) by a bar coating method and baked at 130° C. for 2minutes to form a high refractive-index layer having a thickness of 70nm. Thereafter, Coating Solution A was coated on the highrefractive-index layer by a bar coating method and baked at 130° C. for2 minutes to form a low refractive-index layer having a thickness of 45nm, thereby producing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer. Furthermore, anITO layer was formed on the low refractive-index layer by a sputteringmethod using an indium-tin oxide target having a composition of indiumoxide and tin oxide in a weight ratio of 9:1 and having a packingdensity of 98%, to produce a transparent electroconductive laminate foruse as a movable electrode substrate. The thickness of the ITO layerformed was about 20 nm and the surface resistance was about 280 Ω/□. Thetransparent electroconductive laminate after the ITO layer formation hadthe total luminous transmittance of 93.0% and a haze value of 2.5%.

[0188] Using the movable electrode substrate and a fixed electrodesubstrate with a transparent electroconductive layer produced in thesame manner as in Example 1, a transparent touch panel shown in FIG. 5was produced. A writing durability test of reciprocating straight lines450,000 times under a load of 250 g was performed using apolyacetal-made pen having a tip of 0.8R from the movable electrode sideof the produced transparent touch panel. After the writing durabilitytest, the electrical property (linearity) of the transparent touch panelwas measured and the appearance of the optical interference layer wasobserved. The results are shown in Table 2.

Example 6

[0189] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. Then, on the opposite surface, a curedresin layer (2) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material havingmixed therein silica particles.

[0190] Subsequently, TiO₂ fine particles having a primary diameter of 20nm was mixed in Coating Solution I used in Comparative Example 1 toprepare Coating Solution K where the weight ratio of TiO₂ fine particlesto metal alkoxide was 25:75. Coating Solution K was coated on the silicaparticle-containing cured resin layer (2) by a bar coating method andbaked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 40 nm. Thereafter, Coating Solution A was coatedon the high refractive-index layer by a bar coating method and baked at130° C. for 2 minutes to form a low refractive-index layer having athickness of 40 nm, thereby producing an optical interference layerconsisting of a high refractive-index layer and a low refractive-indexlayer. Furthermore, an ITO layer was formed on the low refractive-indexlayer in the same manner as in Example 5 to produce a transparentelectroconductive laminate for use as a movable electrode substrate. Thetransparent electroconductive laminate after the ITO layer formation hadthe total luminous transmittance of 93.1% and a haze value of 2.4%.

[0191] Separately, on both surfaces of a 75 μm-thick polyethyleneterephthalate film (OFW, produced by Teijin Ltd.), a cured resin layerhaving a thickness of 3 μm was formed using an ultraviolet-curableurethane acrylate resin coating material. The subsequent procedure wasperformed in the same manner as in the production of the movableelectrode substrate above, that is, Coating Solution K was coated on thecured resin layer on one surface by a bar coating method and baked at130° C. for 2 minutes to form a high refractive-index layer having athickness of 40 nm, then Coating Solution A was coated on the highrefractive-index layer by a bar coating method and baked at 130° C. for2 minutes to form a low refractive-index layer having a thickness of 40nm, thereby producing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer, andfurthermore, an ITO layer was formed on the low refractive-index layerin the same manner as in Example 5 to produce a transparentelectroconductive laminate. The transparent electroconductive laminateafter the ITO layer formation had the total luminous transmittance of92.8% and a haze value of 1.7%. A 1.1 mm-thick polycarbonate sheet wasattached using a pressure-sensitive adhesive to this transparentelectroconductive laminate to come into contact with the surfaceopposite the surface where the ITO layer was formed, and then dotspacers with a height of 7 μm, a diameter of 70 μm and a pitch of 1.5 mmwere formed on the ITO layer, whereby a fixed electrode substrate wasproduced.

[0192] Using the produced movable electrode substrate and fixedelectrode substrate, a transparent touch panel shown in FIG. 6 wasproduced. The durability in writing reciprocating straight lines 450,000times under a load of 250 g was examined in the same manner as inExample 5. The test results are shown in Table 2.

Example 7

[0193] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. Then, on the opposite surface, a curedresin layer (2) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material havingmixed therein a silica particle.

[0194] Subsequently, in a mixed solution of a metal alkoxide obtained bymixing Coating Solution I used in Comparative Example 1 and CoatingSolution A to have a Coating Solution I content of 90%, a TiO₂ fineparticle having a primary diameter of 20 nm was mixed to prepare CoatingSolution L where the weight ratio of TiO₂ fine particle to metalalkoxide was 15:85. Coating Solution L was coated on the silicaparticle-containing cured resin layer (2) by a bar coating method andbaked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 40 nm. Thereafter, Coating Solution A was coatedon the high refractive-index layer by a bar coating method and baked at130° C. for 2 minutes to form a low refractive-index layer having athickness of 40 nm, thereby producing an optical interference layerconsisting of a high refractive-index layer and a low refractive-indexlayer. Furthermore, an ITO layer was formed on the low refractive-indexlayer in the same manner as in Example 5 to produce a transparentelectroconductive laminate for use as a movable electrode substrate. Thetransparent electroconductive laminate after the ITO layer formation hadthe total luminous transmittance of 93.4% and a haze value of 2.8%.

[0195] Separately, on both surfaces of a 1.0 mm-thick polycarbonatesheet (PANLIGHT, produced by Teijin Chemicals Ltd.), a cured resin layerhaving a thickness of 3 μm was formed using an ultraviolet-curableurethane acrylate resin coating material. Coating Solution L was coatedon the cured resin layer on one surface by a spin coating method andbaked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 40 nm.

[0196] Subsequently, Coating Solution A was coated on the highrefractive-index layer by a bar coating method and baked at 130° C. for2 minutes to form a low refractive-index layer having a thickness of 40nm, thereby producing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer. Furthermore, anITO layer was formed on the low refractive-index layer in the samemanner as in Example 5 to produce a transparent electroconductivelaminate. The transparent electroconductive laminate after the ITO layerformation had the total luminous transmittance of 94.0% and a haze valueof 1.8%. On the ITO layer, dot spacers with a height of 7 μm, a diameterof 70 μm and a pitch of 1.5 mm were formed, whereby a fixed electrodesubstrate was produced.

[0197] Using the produced movable electrode substrate and the producedfixed electrode substrate, a transparent touch panel shown in FIG. 6 wasproduced. The durability in writing reciprocating straight lines 450,000times under a load of 250 g was examined in the same manner as inExample 5. The test results are shown in Table 2. TABLE 2 Durability byWriting Reciprocating Total Luminous Straight Lines Transmittance300,000 Time Under (%) Haze (%) Load of 250 g Example 5 93.0 2.5 Nochange in both electric property and appearance. Example 6 movablemovable No change in both electrode: 93.1 electrode: 2.4 electricproperty and fixed fixed appearance. electrode: 92.8 electrode: 1.7Example 7 movable movable No change in both electrode: 93.4 electrode:2.8 electric property and fixed fixed appearance. electrode: 94.0electrode: 1.8

Example 8

[0198] On both surfaces of a 188 μm-thick polyethylene terephthalatefilm (OFW, produced by Teijin DuPont Films Japan Limited), a cured resinlayer (1) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material.

[0199] Thereafter, a silica fine particle having an average primarydiameter of 0.5 μm was mixed in Coating Solution I to a ratio of 0.3parts by weight per 100 parts by weight of tetrabutoxytitanate toprepare Coating Solution M.

[0200] Coating Solution M was coated on the cured resin layer (1) by abar coating method and baked at 130° C. for 2 minutes to form a highrefractive-index layer having a thickness of 50 nm. Subsequently,Alkoxysilane Coating Solution A was coated on the high refractive-indexlayer by a bar coating method and baked at 130° C. for 2 minutes to forma low refractive-index layer having a thickness of 45 nm, therebyproducing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer.

[0201] Furthermore, an ITO layer was formed on the low refractive-indexlayer in the same manner as in Example 1 to produce a transparentelectroconductive laminate for use as a movable electrode substrate. Thethickness of the formed ITO layer was about 20 nm and the surfaceresistance was about 280 Ω/□. The transparent electroconductive laminateafter the ITO layer formation had the total luminous transmittance of91.7% and a haze value of 1.4%.

[0202] Using a fixed electrode substrate with a transparentelectroconductive layer produced in the same manner as in Example 5 andthe movable electrode substrate, a transparent touch panel shown in FIG.5 was produced. A durability test of writing reciprocating straightlines 300,000 times under a load of 250 g was performed using apolyacetal-made pen having a tip of 0.8R from the movable electrode sideof the produced transparent touch panel. After the writing durabilitytest, the electrical property (linearity) of the transparent touch panelwas measured and the appearance of the optical interference layer wasobserved.

[0203] In order to confirm a sticking phenomenon between transparentelectroconductive layers of the movable electrode substrate and thefixed electrode substrate, the transparent touch panel was touched underan arbitrary pressure using the above-described pen to put thetransparent electroconductive layers of the movable electrode substrateand the fixed electrode substrates into contact with each other and thepresence or absence of a sticking phenomenon between transparentelectroconductive layers of the movable electrode substrate and thefixed electrode substrates after the pen was moved was examined.Furthermore, the transparent touch panel was disposed on a highresolution color liquid crystal display and how the liquid crystaldisplay was viewed through the transparent touch panel was observed. Theresults are shown in Table 3.

Example 9

[0204] On both surfaces of a 188 μm-thick polyethylene terephthalatefilm (OFW, produced by Teijin DuPont Films Japan Limited), a cured resinlayer (1) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material.

[0205] Thereafter, Coating Solution M and Coating Solution A were mixedat a ratio of 70:30 to prepare Coating Solution N and then, TiO₂ fineparticles having a primary diameter of 20 nm were mixed in CoatingSolution N to prepare Coating Solution O where the weight ratio of TiO₂fine particle and metal alkoxide was 30:70. Coating Solution O wascoated on the cured resin layer (1) by a bar coating method and baked at130° C. for 2 minutes to form a high refractive-index layer having athickness of 55 nm. Subsequently, Coating Solution A used in Example 1was coated on the high refractive-index layer by a bar coating methodand baked at 130° C. for 2 minutes to form a low refractive-index layerhaving a thickness of 40 nm, thereby producing an optical interferencelayer consisting of a high refractive-index layer and a lowrefractive-index layer. Furthermore, an ITO layer was formed on the lowrefractive-index layer in the same manner as in Example 1 to produce atransparent electroconductive laminate for use as a movable electrodesubstrate. The transparent electroconductive laminate after the ITOlayer formation had the total luminous transmittance of 90.1% and a hazevalue of 2.1%.

[0206] Separately, on both surfaces of a 75 μm-thick polyethyleneterephthalate film (OFW, produced by Teijin DuPont Films Japan Limited),a cured resin layer 1 having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material. Thesubsequent procedure was performed in the same manner as in theproduction of the movable electrode substrate above, that is, CoatingSolution L was coated on the cured resin layer 1 by a bar coating methodand baked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 55 nm, then Coating Solution A was coated on thehigh refractive-index layer by a bar coating method and baked at 130° C.for 2 minutes to form a low refractive-index layer having a thickness of40 nm, thereby producing an optical interference layer consisting of ahigh refractive-index layer and a low refractive-index layer, andfurthermore, an ITO layer was formed on the low refractive-index layerin the same manner as in Example 1 to produce a transparentelectroconductive laminate. The transparent electroconductive laminateafter the ITO layer formation had the total luminous transmittance of90.4% and a haze value of 1.9%. A 1.1 mm-thick polycarbonate sheet wasattached using a pressure-sensitive adhesive to this transparentelectroconductive laminate to come into contact with the surfaceopposite the surface where the ITO layer was formed, and then dotspacers with a height of 7 μm, a diameter of 70 μm and a pitch of 1.5 mmwere formed on the ITO layer, whereby a fixed electrode substrate wasproduced.

[0207] Using the produced movable electrode substrate and the producedfixed electrode substrate, a transparent touch panel shown in FIG. 6 wasproduced. After a writing durability test was performed in the samemanner as in Example 8, the electrical property (linearity) of thetransparent touch panel was measured and the appearance of the opticalinterference layer was observed. Also, the presence or absence of asticking phenomenon between transparent electroconductive layers of themovable electrode substrate and the fixed electrode substrates wasexamined. Furthermore, the transparent touch panel was disposed on ahigh resolution color liquid crystal display and how the liquid crystaldisplay was viewed through the transparent touch panel was observed. Thetest results are shown in Table 3.

Comparative Example 2

[0208] On both surfaces of a 188 μm-thick polyethylene terephthalatefilm (OFW, produced by Teijin DuPont Films Japan Limited), a cured resinlayer (1) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material.

[0209] Thereafter, silica fine particles having an average primarydiameter of 0.5 μm were mixed in Coating Solution I used in Example 8 toa ratio of 1.0 part by weight per 100 parts by weight oftetrabutoxytitanate to prepare Coating Solution P. Coating Solution Pwas coated on the cured resin layer (1) by a bar coating method andbaked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 50 nm. Subsequently, Coating Solution A used inExample 8 was coated on the high refractive-index layer by a bar coatingmethod and baked at 130° C. for 2 minutes to form a low refractive-indexlayer having a thickness of 45 nm, thereby producing an opticalinterference layer consisting of a high refractive-index layer and a lowrefractive-index layer. Furthermore, an ITO layer was formed on the lowrefractive-index layer in the same manner as in Example 8 to produce atransparent electroconductive laminate for use as a movable electrodesubstrate. The transparent electroconductive laminate after the ITOlayer formation had the total luminous transmittance of 91.8% and a hazevalue of 2.6%. The produced transparent electroconductive laminate wasslightly white-colored due to the fine particles added in a largeamount.

[0210] Using the movable electrode substrate produced above and a fixedelectrode substrate produced in the same manner as in Example 8, atransparent touch panel shown in FIG. 5 was produced. The transparenttouch panel was disposed on a high resolution color liquid crystaldisplay and how the liquid crystal display was viewed through thetransparent touch panel was observed. The liquid crystal display wasseen indistinctly due to the fine particles added in a large amount andthe visibility was bad.

Comparative Example 3

[0211] On both surfaces of a 188 μm-thick polyethylene terephthalatefilm (OFW, produced by Teijin DuPont Films Japan Limited), a cured resinlayer (1) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material.

[0212] Thereafter, silica fine particles having a primary particle sizeof 1.5 μm were mixed in Coating Solution I used in Example 8 to a ratioof 0.3 parts by weight per 100 parts by weight of tetrabutoxytitanate toprepare Coating Solution Q. Coating Solution Q was coated on the curedresin layer (1) by a bar coating method and baked at 130° C. for 2minutes to form a high refractive-index layer having a thickness of 50nm. Subsequently, Coating Solution A was coated on the highrefractive-index layer by a bar coating method and baked at 130° C. for2 minutes to form a low refractive-index layer having a thickness of 45nm, thereby producing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer.

[0213] Furthermore, an ITO layer was formed on the low refractive-indexlayer in the same manner as in Example 8 to produce a transparentelectroconductive laminate for use as a movable electrode substrate. Thetransparent electroconductive laminate after the ITO layer formation hadthe total luminous transmittance of 91.4% and a haze value of 2.3%.

[0214] Using the movable electrode substrate produced above and a fixedelectrode substrate produced in the same manner as in Example 8, atransparent touch panel shown in FIG. 5 was produced. Then, a writingdurability test was performed in the same manner as in Example 8. At thewriting durability test, the fine particle fell off from the opticalinterference layer due to the large primary diameter of the fineparticle added to the optical interference layer, as a result, theelectric property (linearity) of transparent touch panel and theappearance of optical interference layer were vary bad. Also, thetransparent touch panel was disposed on a high resolution color liquidcrystal display and how the liquid crystal display could seen viewedthrough the transparent touch panel was observed. The liquid crystaldisplay was viewed glaringly due to the large primary diameter of thefine particles added. TABLE 3 Presence or Absence View of Liquid ofSticking Crystal Writing Durability Phenomenon Display Example 8 Nochange in both None Good electric property and appearance. Example 9 Nochange in both None Good electric property and appearance.

Example 10

[0215] On both surfaces of a 188 μm-thick polyethylene terephthalatefilm (OFW, produced by Teijin DuPont Films Japan Limited), a cured resinlayer (1) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material.

[0216] Thereafter, Coating Solution M prepared in Example 8 was coatedon the cured resin layer (1) by a bar coating method and baked at 130°C. for 2 minutes to form a high refractive-index layer having athickness of 50 nm.

[0217] Subsequently, Coating Solution R was prepared using anultraviolet-curable resin comprising 31.3 parts by weight oftrimethylolpropane triacrylate and 62.6 parts by weight ofdimethylolpropane hexaacrylate, a photoinitiator comprising 5.0 parts byweight of 1-hydroxy-cyclohexyl-phenyl-ketone and 1.0 part by weight ofbenzophenone, and a diluent comprising a mixed solvent of isopropylalcohol and 1-methoxy-2-propanol.

[0218] Coating Solution R was coated on the high refractive-index layerby a bar coating method and dried at 60° C. for 2 minutes and then, thecoating film was cured using a high-pressure mercury lamp having anintensity of 160 W/cm under the condition of giving an integrated lightquantity of 300 mJ/cm² to form a low refractive-index layer having athickness of 45 nm, thereby producing an optical interference layerconsisting of a high refractive-index layer and a low refractive-indexlayer. Furthermore, an ITO layer was formed on the low refractive-indexlayer in the same manner as in Example 1 to produce a transparentelectroconductive laminate for use as a movable electrode substrate. Thethickness of the formed ITO layer was about 20 nm and the surfaceresistance was about 280 Ω/□. The transparent electroconductive laminateafter the ITO layer formation had the total luminous transmittance of90.1% and a haze value of 1.4%.

[0219] Separately, a fixed electrode substrate with an ITO layer wasproduced in the same manner as in Example 1. Using the produced fixedelectrode substrate and the produced movable electrode substrate, atransparent touch panel shown in FIG. 5 was produced. A writingdurability test of reciprocating straight lines 300,000 times under aload of 250 g was performed using a polyacetal-made pen having a tip of0.8R from the movable electrode side of the produced transparent touchpanel. After the writing durability test, the electrical property(linearity) of the transparent touch panel was measured and theappearance of the optical interference layer was observed. In order toconfirm a sticking phenomenon between transparent electroconductivelayers of the movable electrode substrate and the fixed electrodesubstrate, the transparent touch panel was touched under an arbitrarypressure using the above-described pen to put the transparentelectroconductive layers of the movable electrode substrate and thefixed electrode substrates into contact with each other and the presenceor absence of a sticking phenomenon between transparentelectroconductive layers of the movable electrode substrate and thefixed electrode substrates after the pen was moved was examined.Furthermore, the transparent touch panel was disposed on a highresolution color liquid crystal display and how the liquid crystaldisplay could be seen through the transparent touch panel was observed.The results are shown in Table 4.

Example 11

[0220] On one surface of a 188 μm-thick polyethylene terephthalate film(OFW, produced by Teijin Ltd.), a cured resin layer (1) having athickness of 3 μm was formed using an ultraviolet-curable urethaneacrylate resin coating material. Then, on the opposite surface, a curedresin layer (2) having a thickness of 3 μm was formed using anultraviolet-curable urethane acrylate resin coating material havingmixed therein a silica particle.

[0221] Thereafter, Coating Solution L of Example 7 was coated on thesilica particle-containing cured resin layer (2) by a bar coating methodand baked at 130° C. for 2 minutes to form a high refractive-index layerhaving a thickness of 55 nm. Subsequently, Coating Solution R used inExample 10 was coated on the high refractive-index layer by a barcoating method and dried at 60° C. for 2 minutes and then, the coatingfilm was cured using a high-pressure mercury lamp having an intensity of160 W/cm under the condition of giving an integrated light quantity of300 mJ/cm² to form a low refractive-index layer having a thickness of 45nm, thereby producing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer. Furthermore, anITO layer was formed on the low refractive-index layer by a sputteringmethod using an indium-tin oxide target having a composition of indiumoxide and tin oxide in a weight ratio of 9:1 and having a packingdensity of 98%, to produce a transparent electroconductive laminate foruse as a movable electrode substrate. The thickness of the formed ITOlayer was about 20 nm and the surface resistance was about 280 Ω/□. Thetransparent electroconductive laminate after the ITO layer formation hadthe total luminous transmittance of 90.6% and a haze value of 2.5%.

[0222] Separately, a fixed electrode substrate with an ITO layer wasproduced in the same manner as in Example 1. Using the produced fixedelectrode substrate and the produced movable electrode substrate, atransparent touch panel shown in FIG. 5 was produced. A durability testof writing reciprocating straight lines 300,000 times under a load of250 g was performed using a polyacetal-made pen having a tip of 0.8Rfrom the movable electrode side of the produced transparent touch panel.After the writing durability test, the electrical property (linearity)of the transparent touch panel was measured and the appearance of theoptical interference layer was observed. The results are shown in Table4. TABLE 4 Presence or Absence View of Liquid of Sticking CrystalWriting Durability Phenomenon Display Example 10 No change in both NoneGood electric property and appearance. Example 11 No change in both NoneGood electric property and appearance.

Examples 12 and 13

[0223]FIG. 3 shows a touch panel using the transparent electroconductivelaminate of Example 12 or 13. In the Figure, 9 is a glass substrate, 5and 10 are a transparent electroconductive layer, 11 is a dot spacer, 1and 8 are a polyethylene terephthalate film, 7 is a transparent elasticlayer, 2, 2′ and 6 are a cured resin layer, 4 is a low refractive-indexlayer, and 3 is a high refractive-index layer. The fixed electrodesubstrate is constituted by the glass substrate 1, the transparentelectroconductive layer 10 and the dot spacer, and the movable electrodesubstrate is constituted by the polyethylene terephthalate films 1 and8, the transparent elastic layer 7, the cured resin layers 2, 2′ and 6,the low refractive-index layer 4, the high refractive-index layer 5 andthe transparent electroconductive layer 10.

[0224] For producing such a touch panel, an SiO₂ layer was stacked onboth surfaces of a 1.1 mm-thick glass substrate 9 by a dip coatingmethod and thereon, an ITO layer having a thickness of 18 nm was stackedas the transparent electroconductive layer 10 by a sputtering method toproduce a glass electrode substrate. On the ITO layer, dot spacers 11with a height of 7 μm, a diameter of 70 μm and a pitch of 1.5 mm wereformed to produce a fixed electrode substrate comprising a glasselectrode substrate.

[0225] Separately, a 75 μm-thick polyethylene terephthalate film (OFW,produced by Teijin, Ltd.) was prepared for use as the organic polymerfilm 1 and the transparent base material 8.

[0226] On one surface of this polyethylene terephthalate film, a coatingsolution containing 1% of a component comprising an oligomer produced bythe hydrolysis of γ-aminopropyltriethoxysilane was coated and dried at130° C. for 5 minutes, thereby performing a primer treatment.Subsequently, a transparent elastic layer 7 having a thickness of 30 μmwas stacked on the primer-treated surface using Coating Solution Ycontaining a silicone resin component comprising polydimethylsiloxane.The Young's modulus of the transparent elastic layer 7 was 1.4×10⁸ Pa.Incidentally, the Young's modulus of a polyethylene terephthalate filmwithout the coated layer measured in the same manner was 5.4×10⁹ Pa. Onthe transparent elastic layer 7, a primer-treated surface of anotherpolyethylene terephthalate film was attached to produce a laminate Rcomprising a polyethylene terephthalate film, a transparent elasticlayer and a polyethylene terephthalate film.

[0227] Thereafter, a cured resin layer 2 or 6 having a thickness of 3 μmwas stacked on both surfaces of the laminate R using anultraviolet-curable urethane acrylate resin coating material to producea laminate S comprising a cured resin layer 2, a polyethyleneterephthalate film 1, a transparent elastic layer 7, a polyethyleneterephthalate film 8 and a cured resin layer 6.

[0228] Coating Solution M prepared in Example 8 was coated on thesurface of the cured resin layer 2 by a bar coating method and baked at130° C. for 2 minutes to form a high refractive-index layer having athickness of 50 nm.

[0229] Then, Alkoxysilane Coating Solution A was coated on the highrefractive-index layer by a bar coating method and baked at 130° C. for2 minutes to form a low refractive-index layer having a thickness of 45nm, thereby producing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer.

[0230] Furthermore, an ITO layer was formed on the low refractive-indexlayer in the same manner as in Example 1 to produce a transparentelectroconductive laminate of Example 12 for use as a movable electrodesubstrate. The thickness of the ITO layer formed was about 20 nm and thesurface resistance was about 280 Ω/□. The transparent electroconductivelaminate after the ITO layer formation had the total luminoustransmittance of 91.0% and a haze value of 1.7%.

[0231] On the other hand, for producing a transparent electroconductivelaminate of Example 13, a cured resin layer 6 having a thickness of 3 μmwas stacked on one surface of the laminate R using anultraviolet-curable urethane acrylate resin coating material. Then, onthe opposite layer, a cured resin layer 2 having a thickness of 3 μm wasstacked using an ultraviolet-curable urethane acrylate resin coatingmaterial having mixed therein a silica particle, to produce a laminate Tcomprising a cured resin layer 6, a polyethylene terephthalate film 8, atransparent elastic layer 7, a polyethylene terephthalate film 1 and acured resin layer 2′.

[0232] Coating Solution L prepared in Example 7 was coated on thesurface of the cured resin layer 2′ by a bar coating method and baked at130° C. for 2 minutes to form a high refractive-index layer having athickness of 50 nm.

[0233] Then, Alkoxysilane Coating Solution A was coated on the highrefractive-index layer by a bar coating method and baked at 130° C. for2 minutes to form a low refractive-index layer having a thickness of 45nm, thereby producing an optical interference layer consisting of a highrefractive-index layer and a low refractive-index layer.

[0234] Furthermore, an ITO layer was formed on the low refractive-indexlayer in the same manner as in Example 1 to produce a transparentelectroconductive laminate of Example 13 for use as a movable electrodesubstrate. The thickness of the ITO layer formed was about 20 nm and thesurface resistance was about 280 Ω/□. The transparent electroconductivelaminate after the ITO layer formation had the total luminoustransmittance of 90.7% and a haze value of 2.8%.

[0235] Using the produced fixed electrode substrate and the producedmovable electrode substrate, a transparent touch panel shown in FIG. 3was produced. A writing durability test of reciprocating straight lines300,000 times under a load of 250 g was performed using apolyacetal-made pen having a tip of 0.8R from the movable electrode sideof the produced transparent touch panel. After the writing durabilitytest, the electrical property (linearity) of the transparent touch panelwas measured and the appearance of the optical interference layer wasobserved.

[0236] The results are shown in Table 5. TABLE 5 Total LuminousDurability by Writing Reciprocating Transmittance Haze Straight Lines300,000 Time Under Example (%) (%) Load of 250 g 12 90.6 2.5 No changein both electric property and appearance. 13 90.7 2.8 No change in bothelectric property and appearance.

INDUSTRIAL APPLICABILITY

[0237] According to the present invention, a crosslinked polymer layerof alkoxysilane containing an ultrafine particle comprising a metaloxide and/or a metal fluoride and having a primary diameter of 100 nm orless is used as the optical interference layer and the weight ratio ofthe ultrafine particle to alkoxysilane is set to a specific ratio,whereby a low-cost transparent electroconductive laminate, havingexcellent transparency and capable of ensuring high reliability in thewriting durability and the like required of the transparent touch panel,is provided. Also, according to the present invention, in the opticalinterference layer comprising a low refractive-index layer and a highrefractive-index layer, a crosslinked polymer layer of alkoxysilane isused as the low refractive-index layer and a crosslinked polymer layerof metal alkoxide mainly other than alkoxysilane is used as the highrefractive-index layer and an ultrafine particle comprising a metaloxide and having a primary diameter of 100 nm or less is contained inthe high refractive-index layer at a specific ratio, whereby a low-costtransparent electroconductive laminate, having excellent transparencyand capable of ensuring high reliability in the writing durability andthe like required of the transparent touch panel is provided.Furthermore, according to the present invention, a transparentelectroconductive laminate having excellent writing durability free ofchange in the electric property and appearance, causing no stickingphenomenon, giving good liquid crystal display and being suitable for atouch panel can be provided.

1. A transparent electroconductive laminate comprising an organicpolymer film having stacked thereon a transparent electroconductivelayer, wherein: an optical interference layer and a transparentelectroconductive layer are sequentially stacked on at least one surfaceof the organic polymer film, the optical interference layer comprises ahigh refractive-index layer and a low refractive-index layer, with thelow refractive-index layer being in contact with the transparentelectroconductive layer, and the high refractive-index layer and the lowrefractive-index layer each is composed of a crosslinked polymer, atleast either one of the high refractive-index layer and the lowrefractive-index layer containing metal oxide and/or metal fluorideultrafine particles having a primary diameter of 100 nm or less.
 2. Thetransparent electroconductive laminate as claimed in claim 1, whereinsaid metal oxide and/or metal fluoride is at least one member selectedfrom the group consisting of Al₂O₃, Bi₂O₃, CeO₂, In₂O₃, In₂O₃.SnO₂,HfO₂, La₂O₃, MgF₂, Sb₂O₅, Sb₂O₅.SnO₂, SiO₂, SnO₂, TiO₂, Y₂O₃, ZnO andZrO₂.
 3. The transparent electroconductive laminate as claimed in claim1 or 2, wherein the crosslinked polymer of at least one of the highrefractive-index layer and the low refractive-index layer is one formedby hydrolysis and condensation polymerization of a metal alkoxide. 4.The transparent electroconductive laminate as claimed in claim 3,wherein the weight ratio of said ultrafine particles to said metalalkoxide is from 5:95 to 80:20.
 5. The transparent electroconductivelaminate as claimed in claim 4, wherein said high refractive-index layeris one formed by hydrolysis and condensation polymerization of a mixturecomprising said ultrafine particles and alkoxysilane at a weight ratioof 5:95 to 80:20.
 6. The transparent electroconductive laminate asclaimed in claim 3, wherein said high refractive-index layer is oneformed by hydrolysis and condensation polymerization of a mixturecomprising said ultrafine particles and a metal alkoxide at a weightratio of 1:99 to 60:40 and said metal alkoxide is mainly comprised of ametal alkoxide other than alkoxysilane.
 7. The transparentelectroconductive laminate as claimed in claim 1, wherein said highrefractive-index layer is composed of a mixture comprising saidultrafine particles and said thermosetting resin or radiation-curableresin at a polymerization ratio of 5:95 to 80:20.
 8. The transparentelectroconductive laminate as claimed in claim 1 or 2, wherein saidcrosslinked polymer of at least one of the high refractive-index layerand the low refractive-index layer is a thermosetting resin or aradiation-curable resin.
 9. The transparent electroconductive laminateas claimed in any one of claims 1 to 8, wherein the difference in therefractive index between the high refractive-index layer and the lowrefractive-index layer is 0.2 or more.
 10. The transparentelectroconductive laminate as claimed in any one of claims 1 to 9,wherein at least one of said high refractive-index layer and said lowrefractive-index layer contains second fine particles having an averageprimary diameter as large as 1.1 times or more the thickness of saidoptical interference layer and an average primary diameter of 1.2 μm orless, and the content of said second fine particles is 0.5 wt % or lessof the crosslinked polymer component constituting the highrefractive-index layer and/or low refractive-index layer containing saidsecond fine particles.
 11. The transparent electroconductive laminate asclaimed in any one of claims 1 to 10, which comprises a cured resinlayer between said organic polymer film and said optical interferencelayer.
 12. The transparent electroconductive laminate as claimed in anyone of claims 1 to 11, wherein said cured resin layer is composed of athermosetting or radiation-curable resin and has a thickness of 2 to 5μm.
 13. The transparent electroconductive laminate as claimed in claim11 or 12, wherein said cured resin layer contains third fine particles.14. The transparent electroconductive laminate as claimed in claim 1,wherein said high refractive-index layer is one formed by hydrolysis andcondensation polymerization of a mixture comprising said ultrafineparticles and a metal alkoxide, said metal alkoxide is mainly comprisedof a metal alkoxide other than alkoxysilane, said low refractive-indexlayer is one formed by hydrolysis and condensation polymerization ofalkoxysilane, said ultrafine particle is TiO₂, and said third fineparticles are silica particles.
 15. The transparent electroconductivelaminate as claimed in any one of claims 1 to 14, wherein a transparentsubstrate is stacked on the surface of said organic polymer filmopposite said optical interference layer, through a transparent elasticlayer having a Young's modulus smaller than that of said organic polymerfilm.
 16. A transparent electroconductive laminate comprising an organicpolymer film having stacked thereon a transparent electroconductivelayer, wherein an optical interference layer and a transparentelectroconductive layer are sequentially stacked on at least one surfaceof the organic polymer film, the optical interference layer comprises ahigh refractive-index layer and a low refractive-index layer, with saidlow refractive-index layer being in contact with the transparentelectroconductive layer, said optical interference layer is composed ofa crosslinked polymer, at least one of said high refractive-index layerand said low refractive-index layer contains a fine particles B havingan average primary diameter as large as 1.1 times or more the thicknessof the optical interference layer and an average primary diameter of 1.2μm or less, and the content of said fine particle B is 0.5 wt % or lessof the crosslinked polymer constituting the high refractive-index layerand/or low refractive-index layer containing said fine particle B. 17.The transparent electroconductive laminate as claimed in claim 16,wherein the crosslinked polymer is a polymer formed by hydrolysis andcondensation polymerization of a metal alkoxide or is a thermosetting orradiation-curable resin.
 18. The transparent electroconductive laminateas claimed in claim 16 or 17, wherein at least one of the highrefractive-index layer and the low refractive-index layer contains anultrafine particles A having an average primary diameter of 100 nm orless at a weight ratio (ultrafine particle A): (crosslinked polymer) of0:100 to 80:20.
 19. The transparent electroconductive laminate asclaimed in claim 18, wherein said high refractive-index layer iscomposed of a mixture comprising said ultrafine particles A and saidthermosetting or radiation-curable resin at a polymerization ratio of5:95 to 80:20.
 20. The transparent electroconductive laminate as claimedin any one of claims 16 to 19, which comprises a cured resin layerbetween said organic polymer film and said optical interference layer.21. The transparent electroconductive laminate as claimed in claim 20,wherein said cured resin layer is composed of a thermosetting orradiation-curable resin and has a thickness of 2 to 5 μm.
 22. Thetransparent electroconductive laminate as claimed in claim 20 or 21,wherein said cured resin layer does not contain a fine particle largerthan the thickness of said cured resin layer.
 23. The transparentelectroconductive laminate as claimed in claim 16, wherein said highrefractive-index layer is one formed by hydrolysis and condensationpolymerization of a mixture comprising said fine particles B and a metalalkoxide, said metal alkoxide is mainly comprised of a metal alkoxideother than alkoxysilane, the low refractive-index layer is one formed byhydrolysis and condensation polymerization of alkoxysilane, and saidfine particles B are silica.
 24. The transparent electroconductivelaminate as claimed in any one of claims 16 to 23, wherein a transparentsubstrate is stacked on the surface of said organic film layer oppositesaid optical interference layer, through a transparent elastic layerhaving a Young's modulus smaller than that of said organic polymer film.25. A transparent touch panel comprising two transparent electrodesubstrates each having on at least one surface thereof a transparentelectroconductive layer, the two transparent electrode substrates beingdisposed such that the transparent electroconductive layers face eachother, wherein at least one transparent electrode substrate is thetransparent electroconductive laminate claimed in any one of claims 1 to24.
 26. The transparent touch panel as claimed in claim 25, wherein amovable electrode substrate and a fixed electrode substrate both aresaid transparent electroconductive laminate.